Additive manufacturing systems and methods of pretreating and additively printing on workpieces

ABSTRACT

Methods of additively printing an extension segment on a workpiece may include pretreating a workpiece-interface of a workpiece using an energy beam from an additive manufacturing machine, providing a pretreated workpiece-interface having received a pretreatment, with the pretreatment remediating an aberrant feature of the workpiece and/or the workpiece-interface. Such methods may additionally include additively printing an extension segment on the pretreated workpiece-interface using the energy beam from the additive manufacturing machine. Exemplary additive manufacturing system for printing an extension segment on a workpiece may include a controller operably coupled to a vision system and an additive manufacturing machine.

FIELD

The present disclosure generally pertains to additive manufacturingsystems and methods of additively printing on workpieces, and moreparticularly to systems and methods that include a vision systemconfigured to locate workpieces and an additive manufacturing machineconfigured to pretreat workpieces and additively print on the pretreatedworkpieces.

BACKGROUND

An additive manufacturing machine or system may be utilized to producecomponents according to a three-dimensional computer model. A model ofthe component may be constructed using a computer aided design (CAD)program, and an additive manufacturing machine or system may additivelyprint the component according to the model. With previous additivemanufacturing machines or systems, typically, components are additivelyprinted on a build plate and/or within a build chamber. After theadditive printing process is completed, the components are removed fromthe build plate and/or the build chamber for further processing. Thebuild plate and/or the build chamber are not part of the component beingadditively printed, but rather, the build plate and the build chamberrespectively provide a surface and/or a medium to support componentsduring the additive printing process. As a result, the specific locationof the final additively printed components on the build plate and/orwithin the build chamber may not be of particular importance providedthat the components are successfully printed as intended by the CADmodel.

However, according to the present disclosure, it would be desirable toutilize an additive manufacturing machine or system to additively printonto pre-exiting workpieces, including additively printing onto aplurality of pre-existing workpieces as part of a single build. Whenadditively printing onto such workpieces, it would be desirable foradditive manufacturing machines, systems, and methods to additivelyprint onto pre-existing workpieces with sufficient precision andaccuracy so as to provide near net shape components. Accordingly, thereexists a need for improved additive manufacturing machines and systems,and methods of additively printing on workpieces.

It is contemplated in the present disclosure that when additivelyprinting on a workpiece, it is desirable for the material additivelyprinted thereon to sufficiently bond with the workpiece. In apowder-based additive manufacturing system, sequential layers of powderare bonded (e.g., melted or fused) to one another using an energy sourcethat has a focal point generally corresponding to the elevation of thelayer of powder being melted or fused to material immediately below suchlayer. However, when additively printing on a pre-existing workpiece,variation in the elevation across a surface of a workpiece may causevariations or interruptions in the powder spread across the surface ofthe workpiece as well as the bond between the surface of the workpieceand the sequential layer of powder being melted or fused thereto.Additionally, the surface of a pre-existing workpiece may have oxidationor other surface features that may affect the bonding of powder thereto.Accordingly, there further exists a need for improved additivemanufacturing machines and systems, and methods of pretreating andadditively printing on workpieces.

The workpieces contemplated by the present disclosure include originallyfabricated workpieces, as well as workpieces intended to be repaired,rebuilt, upgraded, and so forth, such as machine or device componentsthat may experience damage, wear, and/or degradation throughout theirservice life. It would be desirable to additively print on workpiecessuch as machine or device components so as to repair, rebuild, orupgrade such components. It would also be desirable to additively printon workpieces so as to produce new components such as components thatmay exhibit an enhanced performance or service life.

One example of a machine or device component includes an air foil, suchas a compressor blade or a turbine blade used in a turbomachine. Theseair foils frequently experience damage, wear, and/or degradationthroughout their service life. For example, serviced air foils, such ascompressor blades of a gas turbine engine show erosion, defects, and/orcracks after long term use. Specifically, for example, such blades aresubject to significant high stresses and temperatures which inevitablycause blades to wear over time, particularly near the tip of the blade.For example, blade tips are susceptible to wear or damage from frictionor rubbing between the blade tips and turbomachine shrouds, fromchemical degradation or oxidation from hot gasses, from fatigue causedby cyclic loading and unloading, from diffusion creep of crystallinelattices, and so forth.

Notably, worn or damaged blades may result in machine failure orperformance degradation if not corrected. Specifically, such blades maycause a turbomachine to exhibit reduced operating efficiency as gapsbetween blade tips and turbomachine shrouds may allow gasses to leakthrough the turbomachine stages without being converted to mechanicalenergy. When efficiency drops below specified levels, the turbomachineis typically removed from service for overhaul and repair. Moreover,weakened blades may result in complete fractures and catastrophicfailure of the engine.

As a result, compressor blades for a turbomachine are typically thetarget of frequent inspections, repairs, or replacements. It istypically expensive to replace such blades altogether, however, some canbe repaired for extended lifetime at relatively low cost (as compared toreplacement with new blades). Nevertheless, traditional repair processestend to be labor intensive and time consuming.

For example, a traditional repair process uses a welding/claddingtechnique whereby repair material may be supplied to a repair surface ineither powder or wire form, and the repair material may be melted andbonded to the repair surface using a focused power source such as alaser, e-beam, plasma arc, or the like. However, blades repaired withsuch a welding/cladding technique also undergo tedious post-processingto achieve the target geometry and surface finish. Specifically, due tothe bulky feature size of the welding/cladding repair material bonded tothe repair surface, the repaired blades require heavy machining toremove extra material followed by polishing to achieve a target surfacefinish. Notably, such machining and polishing processes are performed ona single blade at a time, are labor intensive and tedious, and result inlarge overall labor costs for a single repair.

Alternatively, other direct-energy-deposition (DED) methods may be usedfor blade repair, e.g., such as cold spray, which directs high-speedmetal powders to bombard the target or base component such that thepowders deform and deposit on the base component. However, none of theseDED methods are suitable for batch processing or for repairing a largenumber of components in a time-efficient manner, thus providing littleor no business value.

Accordingly, it would be desirable to provide improved system and methodfor repairing or rebuilding serviced components. More particularly,additive manufacturing machines and systems for quickly and effectivelyrebuilding or repairing worn compressor blades would be particularlydesirable.

BRIEF DESCRIPTION

Aspects and advantages will be set forth in part in the followingdescription, or may be obvious from the description, or may be learnedthrough practicing the presently disclosed subject matter.

In one aspect, the present disclosure embraces methods of additivelyprinting an extension segment on a workpiece. An exemplary method mayinclude pretreating a workpiece-interface of a workpiece using an energybeam from an additive manufacturing machine, providing a pretreatedworkpiece-interface having received a pretreatment, with thepretreatment remediating an aberrant feature of the workpiece and/or theworkpiece-interface. An exemplary method may additionally includeadditively printing an extension segment on the pretreatedworkpiece-interface using the energy beam from the additivemanufacturing machine.

In another aspect, the present disclosure embraces additivemanufacturing systems. An exemplary additive manufacturing system mayinclude a controller operably coupled to a vision system and an additivemanufacturing machine. The controller may include one or more computerreadable medium and one or more processors, and the one or more computerreadable medium may include computer-executable instructions, which,when executed by the one or more processors, cause the additivemanufacturing system to pretreat a workpiece interface, providing apretreated workpiece-interface, and/or additively print an extensionsegment on the pretreated workpiece-interface. Pretreating a workpieceinterface may be performed using an energy beam from the additivemanufacturing machine. Pretreating the workpiece-interface may includeadditive-leveling the workpiece-interface and/or melt-leveling theworkpiece-interface. Additively printing an extension segment on thepretreated workpiece-interface may be performed using the energy beamfrom the additive manufacturing machine.

In yet another aspect, the present disclosure embraces computer readablemedium including computer-executable instructions, which, when executedby one or more processors of an additive manufacturing system, cause theadditive manufacturing system to pretreat a workpiece-interface using anenergy beam from the additive manufacturing machine, providing apretreated workpiece-interface, with pretreat the workpiece-interfacecomprises additive-leveling the workpiece-interface and/or melt-levelingthe workpiece-interface. The computer readable medium may additionallyinclude computer-executable instructions, which, when executed by one ormore processors of an additive manufacturing system, cause the additivemanufacturing system to additively print an extension segment on thepretreated workpiece-interface using the energy beam from the additivemanufacturing machine.

These and other features, aspects and advantages will become betterunderstood with reference to the following description and appendedclaims. The accompanying drawings, which are incorporated in andconstitute a part of this specification, illustrate exemplaryembodiments and, together with the description, serve to explain certainprinciples of the presently disclosed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure, including the best mode thereof,directed to one of ordinary skill in the art, is set forth in thespecification, which makes reference to the appended Figures, in which:

FIGS. 1A and 1B schematically depict exemplary additive manufacturingsystems;

FIG. 2A schematically depicts an exemplary workpiece-assembly thatincludes a plurality of workpieces secured to a build plate;

FIG. 2B schematically depicts the exemplary workpiece-assembly of FIG.2A, with a plurality of components by additively printing extensionsegments the plurality of workpieces secured to the build plate;

FIGS. 3A and 3B respectively depict a plurality of workpieces misalignedwith a build plane, and a recoater consequently failing to successfullyapply a uniform layer of powder across the build plane;

FIGS. 3C and 3D respectively depict a plurality of workpieces alignedwith a build plane, and a recoater successfully applying a uniform layerof powder across the build plane;

FIG. 4 shows a flowchart depicting an exemplary method of additivelyprinting an extension segment on a workpiece-interface of a workpiece;

FIGS. 5A and 5B schematically depicts an exemplary workpiece before andafter subjecting the workpiece to a subtractive modification,respectively;

FIG. 5C schematically depicts an exemplary component formed byadditively printing an extension segment on the workpiece depicted inFIG. 5B;

FIG. 6A schematically depicts an exemplary digital representation of afield of view that includes a workpiece, captured using a vision system;

FIG. 6B schematically depicts an exemplary digital representation of oneor more fields of view that includes a plurality of workpieces, capturedusing the vision system;

FIG. 7A shows a flowchart depicting an exemplary method of determining aworkpiece, a workpiece-interface, and/or a workpiece-interfaceperimeter:

FIG. 7B shows a flowchart depicting an exemplary method of generating aprint command;

FIG. 8A schematically depicts an exemplary extension segment-CAD modelthat include a model of a plurality of extension segments;

FIG. 8B schematically depicts an exemplary library-CAD model thatincludes a nominal model of a plurality of nominal workpieces;

FIGS. 9A and 9B show a flowchart depicting an exemplary method ofgenerating an extension segment-CAD model;

FIGS. 10A-10D schematically depict exemplary transforming operationswhich may be performed so as to conform a nominal model-interface to adigital representation of a workpiece-interface, such as in theexemplary method depicted in FIGS. 9A and 9B;

FIG. 11A schematically depicts an exemplary nominal model, such as froma library-CAD model;

FIG. 11B schematically depicts an exemplary model of an extensionsegment, such as in an extension segment-CAD model:

FIGS. 12A-12D show flowcharts depicting exemplary methods of extending amodel-interface which may be performed so as to define a model of anextension segment extending in the z-direction from a model-interface toa nominal extended-plane, such as in the exemplary method depicted inFIGS. 9A and 9B:

FIG. 13 schematically depicts an exemplary print command for additivelyprinting a slice of a plurality of extension segments:

FIG. 14 shows a flowchart depicting an exemplary method of generating apretreatment command;

FIGS. 15A-15R schematically depict exemplary aberrantworkpiece-interfaces, exemplary pretreatment-CAD models, and exemplarypretreated workpiece-interfaces respectively corresponding to oneanother;

FIG. 16A schematically depicts a digital representation of a pluralityof workpieces having an aberrant workpiece-interface, with theworkpieces situated in a workpiece alignment system and ascratch-coating of powder applied thereto;

FIG. 16B; schematically depicts a digital representation of a pluralityof workpieces situated in a workpiece alignment system after having apretreatment applied to the aberrant workpiece-interfaces thereof;

FIG. 17 schematically depicts an enlarged view of an exemplarypretreated workpiece-interface;

FIGS. 18A and 18B show a flowchart depicting an exemplary method ofgenerating a pretreatment-CAD model:

FIG. 19 schematically depicts an exemplary pretreatment command forpretreating a plurality of aberrant workpiece-interfaces;

FIG. 20 schematically depicts an exemplary calibration-CAD model:

FIG. 21 schematically depicts an exemplary calibration surface thatincludes a plurality of printed calibration marks that were printedusing an additive manufacturing machine:

FIG. 22 schematically depicts an exemplary digital representation of afield of view that includes a plurality of calibration marks having beenobtained using a vision system;

FIG. 23 schematically depicts an exemplary comparison table illustratingan exemplary comparison of respective ones of a plurality of digitallyrepresented calibration marks to corresponding respective ones of aplurality of model calibration marks;

FIG. 24A schematically depicts an exemplary digital representation of aworkpiece-interface obtained from a vision system before calibration andafter calibration, such as for a calibration adjustment applied to thevision system:

FIG. 24B schematically depicts an exemplary location of an extensionsegment additively printed using an additive manufacturing machinebefore calibration and after calibration, such as for a calibrationadjustment applied to the additive manufacturing machine:

FIG. 24C schematically depicts an exemplary location of a model of anextension segment in an extension-segment CAD model before calibrationand after calibration, such as for a calibration adjustment applied tothe extension-segment CAD model;

FIG. 25 shows a flowchart depicting an exemplary method of calibratingan additive manufacturing system; and

FIG. 26 shows a block diagram depicting an exemplary control system ofan additive manufacturing system.

Repeat use of reference characters in the present specification anddrawings is intended to represent the same or analogous features orelements of the present disclosure.

DETAILED DESCRIPTION

Reference now will be made in detail to exemplary embodiments of thepresently disclosed subject matter, one or more examples of which areillustrated in the drawings. Each example is provided by way ofexplanation and should not be interpreted as limiting the presentdisclosure. In fact, it will be apparent to those skilled in the artthat various modifications and variations can be made in the presentdisclosure without departing from the scope or spirit of the presentdisclosure. For instance, features illustrated or described as part ofone embodiment can be used with another embodiment to yield a stillfurther embodiment. Thus, it is intended that the present disclosurecovers such modifications and variations as come within the scope of theappended claims and their equivalents.

It is understood that terms such as “op”, “bottom”, “outward”, “inward”,and the like are words of convenience and are not to be construed aslimiting terms. As used herein, the terms “first”, “second”, and “third”may be used interchangeably to distinguish one component from anotherand are not intended to signify location or importance of the individualcomponents. The terms “a” and “an” do not denote a limitation ofquantity, but rather denote the presence of at least one of thereferenced item.

Here and throughout the specification and claims, range limitations arecombined and interchanged, and such ranges are identified and includeall the sub-ranges contained therein unless context or languageindicates otherwise. For example, all ranges disclosed herein areinclusive of the endpoints, and the endpoints are independentlycombinable with each other.

Approximating language, as used herein throughout the specification andclaims, is applied to modify any quantitative representation that couldpermissibly vary without resulting in a change in the basic function towhich it is related. Accordingly, a value modified by a term or terms,such as “about”, “approximately”, and “substantially”, are not to belimited to the precise value specified. In at least some instances, theapproximating language may correspond to the precision of an instrumentfor measuring the value, or the precision of the methods or machines forconstructing or manufacturing the components and/or systems.

As described in detail below, exemplary embodiments of the presentsubject matter involve the use of additive manufacturing machines ormethods. As used herein, the terms “additively manufactured” or“additive manufacturing techniques or processes” refer generally tomanufacturing processes wherein successive layers of material(s) areprovided on each other to “build-up,” layer-by-layer, athree-dimensional component. The successive layers generally fusetogether to form a monolithic component which may have a variety ofintegral sub-components.

As used herein, the term “near net shape” refers to an additivelyprinted feature that has an as-printed shape that is very close to thefinal “net” shape. A near net shape component may undergo surfacefinishing such as polishing, buffing, and the like, but does not requireheaving machining so as to achieve a final “net” shape. By way ofexample, a near net shape may differ from a final net shape by about1,500 microns or less, such as about 1,000 μm or less, such as about 500μm or less, such as about 250 μm or less, such as about 150 μm or less,such as about 100 μm or less, such as about 50 μm or less, or such asabout 25 μm or less.

Although additive manufacturing technology is described herein asenabling fabrication of complex objects by building objectspoint-by-point, layer-by-layer, typically in a vertical direction, othermethods of fabrication are possible and within the scope of the presentsubject matter. For example, although the discussion herein refers tothe addition of material to form successive layers, one skilled in theart will appreciate that the methods and structures disclosed herein maybe practiced with any additive manufacturing technique or manufacturingtechnology. For example, embodiments of the present invention may uselayer-additive processes, layer-subtractive processes, or hybridprocesses.

Suitable additive manufacturing techniques in accordance with thepresent disclosure include, for example, Fused Deposition Modeling(FDM), Selective Laser Sintering (SLS), 3D printing such as by inkjetsand laserjets, Sterolithography (SLA), Direct Selective Laser Sintering(DSLS), Electron Beam Sintering (EBS), Electron Beam Melting (EBM),Laser Engineered Net Shaping (LENS), Laser Net Shape Manufacturing(LNSM), Direct Metal Deposition (DMD), Digital Light Processing (DLP),Direct Selective Laser Melting (DSLM), Selective Laser Melting (SLM),Direct Metal Laser Melting (DMLM), and other known processes.

In addition to using a direct metal laser sintering (DMLS) or directmetal laser melting (DMLM) process where an energy source is used toselectively sinter or melt portions of a layer of powder, it should beappreciated that according to alternative embodiments, the additivemanufacturing process may be a “binder jetting” process. In this regard,binder jetting involves successively depositing layers of additivepowder in a similar manner as described above. However, instead of usingan energy source to generate an energy beam to selectively melt or fusethe additive powders, binder jetting involves selectively depositing aliquid binding agent onto each layer of powder. The liquid binding agentmay be, for example, a photo-curable polymer or another liquid bondingagent. Other suitable additive manufacturing methods and variants areintended to be within the scope of the present subject matter.

The additive manufacturing processes described herein may be used forforming components using any suitable material. For example, thematerial may be plastic, metal, concrete, ceramic, polymer, epoxy,photopolymer resin, or any other suitable material that may be in solid,liquid, powder, sheet material, wire, or any other suitable form. Morespecifically, according to exemplary embodiments of the present subjectmatter, the additively manufactured components described herein may beformed in part, in whole, or in some combination of materials includingbut not limited to pure metals, nickel alloys, chrome alloys, titanium,titanium alloys, magnesium, magnesium alloys, aluminum, aluminum alloys,iron, iron alloys, stainless steel, and nickel or cobalt basedsuperalloys (e.g., those available under the name Inconel® availablefrom Special Metals Corporation). These materials are examples ofmaterials suitable for use in the additive manufacturing processesdescribed herein and may be generally referred to as “additivematerials.”

In addition, one skilled in the art will appreciate that a variety ofmaterials and methods for bonding those materials may be used and arecontemplated as within the scope of the present disclosure. As usedherein, references to “fusing” may refer to any suitable process forcreating a bonded layer of any of the above materials. For example, ifan object is made from polymer, fusing may refer to creating a thermosetbond between polymer materials. If the object is epoxy, the bond may beformed by a crosslinking process. If the material is ceramic, the bondmay be formed by a sintering process. If the material is powdered metal,the bond may be formed by a melting or sintering process. One skilled inthe art will appreciate that other methods of fusing materials to make acomponent by additive manufacturing are possible, and the presentlydisclosed subject matter may be practiced with those methods.

In addition, the additive manufacturing process disclosed herein allowsa single component to be formed from multiple materials. Thus, thecomponents described herein may be formed from any suitable mixtures ofthe above materials. For example, a component may include multiplelayers, segments, or parts that are formed using different materials,processes, and/or on different additive manufacturing machines. In thismanner, components may be constructed which have different materials andmaterial properties for meeting the demands of any particularapplication. In addition, although the components described herein areconstructed by additive manufacturing processes, it should beappreciated that in alternate embodiments, all or a portion of thesecomponents may be formed via casting, machining, and/or any othersuitable manufacturing process. Indeed, any suitable combination ofmaterials and manufacturing methods may be used to form thesecomponents.

An exemplary additive manufacturing process will now be described.Additive manufacturing processes fabricate components usingthree-dimensional (3D) information, for example a three-dimensionalcomputer model, of the component. Accordingly, a three-dimensionaldesign model of the component may be defined prior to manufacturing. Inthis regard, a model or prototype of the component may be scanned todetermine the three-dimensional information of the component. As anotherexample, a model of the component may be constructed using a suitablecomputer aided design (CAD) program to define the three-dimensionaldesign model of the component.

The design model may include 3D numeric coordinates of the configurationof the component including both external and internal surfaces of thecomponent. For example, the design model may define the body, thesurface, and/or internal passageways such as openings, supportstructures, etc. In one exemplary embodiment, the three-dimensionaldesign model is converted into a plurality of slices or segments, e.g.,along a central (e.g., vertical) axis of the component or any othersuitable axis. Each slice may define a thin cross section of thecomponent for a predetermined height of the slice. The plurality ofsuccessive cross-sectional slices together form the 3D component. Thecomponent is then “built-up” slice-by-slice, or layer-by-layer, untilfinished.

In this manner, the components described herein may be fabricated usingthe additive process, or more specifically each layer is successivelyformed, e.g., by fusing or polymerizing a plastic using laser energy orheat or by sintering or melting metal powder. For example, a particulartype of additive manufacturing process may use an energy beam, forexample, an electron beam or electromagnetic radiation such as a laserbeam, to sinter or melt a powder material. Any suitable laser and laserparameters may be used, including considerations with respect to power,laser beam spot size, and scanning velocity. The build material may beformed by any suitable powder or material selected for enhancedstrength, durability, and useful life, particularly at hightemperatures.

Each successive layer may be, for example, between about 10 μm and 200μm, although the thickness may be selected based on any number ofparameters and may be any suitable size according to alternativeembodiments. Therefore, utilizing the additive formation methodsdescribed above, the components described herein may have cross sectionsas thin as one thickness of an associated powder layer, e.g., 10 μm,utilized during the additive formation process.

In addition, utilizing an additive process, the surface finish andfeatures of the components may vary as need depending on theapplication. For example, the surface finish may be adjusted (e.g., madesmoother or rougher) by selecting appropriate laser scan parameters(e.g., laser power, scan speed, laser focal spot size, etc.) during theadditive process, especially in the periphery of a cross-sectional layerwhich corresponds to the part surface. For example, a rougher finish maybe achieved by increasing laser scan speed or decreasing the size of themelt pool formed, and a smoother finish may be achieved by decreasinglaser scan speed or increasing the size of the melt pool formed. Thescanning pattern and/or laser power can also be changed to change thesurface finish in a selected area.

After fabrication of the component is complete, various post-processingprocedures may be applied to the component. For example, post processingprocedures may include removal of excess powder by, for example, blowingor vacuuming. Other post processing procedures may include a stressrelief process. Additionally, thermal, mechanical, and/or chemical postprocessing procedures can be used to finish the part to achieve adesired strength, surface finish, and other component properties orfeatures.

Notably, in exemplary embodiments, several aspects and features of thepresent subject matter were previously not possible due to manufacturingrestraints. However, the present inventors have advantageously utilizedcurrent advances in additive manufacturing techniques to improve variouscomponents and the method of additively manufacturing such components.While the present disclosure is not limited to the use of additivemanufacturing to form these components generally, additive manufacturingdoes provide a variety of manufacturing advantages, including ease ofmanufacturing, reduced cost, greater accuracy, etc.

Also, the additive manufacturing methods described above enable muchmore complex and intricate shapes and contours of the componentsdescribed herein to be formed with a very high level of precision. Forexample, such components may include thin additively manufacturedlayers, cross sectional features, and component contours. In addition,the additive manufacturing process enables the manufacture of a singlecomponent having different materials such that different portions of thecomponent may exhibit different performance characteristics. Thesuccessive, additive nature of the manufacturing process enables theconstruction of these novel features. As a result, components formedusing the methods described herein may exhibit improved performance andreliability.

The present disclosure generally provides additive manufacturingmachines, systems, and methods configured to pretreat and additivelyprint on pre-existing workpieces. The pre-existing workpieces mayinclude new workpieces as well as workpieces being repaired, rebuilt, orupgraded. The presently disclosed additive manufacturing systems andmethods utilize a vision system to capture digital representations ofone or more workpieces situated in a field of view, which may be in theform of digital images or the like. The shape and location of eachworkpiece may be determined using the vision system and pretreatmentcommands and/or print commands may be generated based at least in parton the digital representation of the one or more workpieces. Thepretreatment commands may be configured to cause an additivemanufacturing machine to utilize an energy source of the additivemanufacturing machine to pretreat one or more workpieces, and the printcommands may be configured to cause an additive manufacturing machine toadditively print an extension segment directly on each of the one ormore workpieces.

The workpieces may include a workpiece-interface, which refers to asurface that may be pretreated using the energy source from the additivemanufacturing machine and upon which an additive manufacturing machinemay additively print an extension segment. For some workpieces, theworkpiece-interface may include a surface that has undergonepre-processing prior to such pretreatment and in preparation foradditively printing. For example, a surface may be machined, ground,brushed, etched, polished, or otherwise substantively modified so as toprovide a workpiece-interface. Such subtractive modification may removeat least a portion of a surface that has been worn or damaged, and/ormay improve bonding between the workpiece and the additively printedmaterial. In the case of previously used components, such as compressorblades or turbine blades, the surface may be damaged or worn to somedegree, including artifacts such as microcracks, pits, abrasions,defects, foreign material, depositions, imperfections, and the like. Thesubtractive modification process may remove such damage or wear toprovide a workpiece with a workpiece-interface that is ready foradditive printing. The workpiece-interface resulting from suchsubtractive modification may be pretreated according to the presentdisclosure, and an extension segment may be additively printed on thepretreated workpiece-interface. However, in some embodiments, thesubtractive modification and/or the pretreatment may be omitted, forexample, when a workpiece includes a workpiece-interface suitable foradditively printing thereon. Of course, a subtractive modificationand/or a pretreatment may be performed even when a workpiece includes asuitable workpiece-interface, for example, to provide an improvedworkpiece-interface.

One exemplary type of workpiece includes airfoils for a turbomachine,such as compressor blades and/or turbine blades. A typical turbomachineincludes one or more compressor sections, each of which may includemultiple compressor stages, and one or more turbine sections, each ofwhich may include multiple turbine stages. The compressor sections andturbine sections are typically oriented along an axis of rotation andrespectively include a series of airfoils disposed circumferentiallyaround the respective stage and circumferentially surrounded by ashroud.

Typically, the nature and extent of damage or wear to a set of bladesremoved from a turbomachine for repair or rebuild varies from blade toblade. As a result, the amount of material that may need to be removedduring a subtractive modification process so as to prepare aworkpiece-interface may vary from one blade to the next. Additionally,some of the blades may be deformed from their original net shape throughexposure to high stresses and temperatures and/or through damage fromrubbing on shrouds and so forth. As a result, each individual blade maydiffer from its original net shape in varying degrees from one blade tothe next.

Additionally, the size and shape of the airfoils may differ from onestage to the next, and the tips of the airfoils provides a relativelysmall workpiece-interface. As an example, exemplary high-pressurecompressor blades may be about 1 to 2 inches tall and may have a bladetip with a cross-sectional width of about 0.5 mm to about 5 mm, whichprovides for a particularly small workpiece-interface, which providesfor a particularly small workpiece-interface. Other exemplaryhigh-pressure compressor blades, as well as low-pressure compressorblades and blades from a turbine section (e.g., high-pressure turbineblades and low-pressure turbine blades) may be somewhat larger, such asup to about 10 inches tall, but nevertheless provide for a smallworkpiece-interface.

This variability from one workpiece to the next, including variabilityas to differences from original net shape, differing amounts ofsubtractive modification, and/or differences in size and shape, presentsseveral key challenges in additively printing on the workpiece-interfaceof such workpieces, which are addressed by the present disclosure. Inparticular, the present disclosure provides for additively printingextension segments on the workpiece-interface of respective workpieceswith sufficient precision and accuracy so as to provide near net shapecomponents even though the respective workpieces may differ from oneanother because of one or more of such sources of variability.

In some embodiments, the present disclosure provides systems and methodsof securing workpieces to a build plate and/or within a build chamber sothat an additive manufacturing machine or system may additively printonto the workpiece-interfaces of the respective workpieces as part of acommon build even when the workpieces have different sizes or shapes.For example, the present disclosure provides build plates that includeone or more biasing members configured to align the workpiece-interfaceswith one another, and one or more clamping mechanisms which operate tosecure the workpieces to the build plate. The workpieces may be securedto the build plate at locations which may be determined by registrationpoints mapped to a coordinate system that may be utilized by theadditive manufacturing system to locate the workpieces and/or theirworkpiece-interfaces.

The present disclosure provides systems and methods of pretreatingworkpiece-interfaces, such as those having one or more aberrantfeatures. The pretreatment may remediate aberrant features and/orenhance one or more features of the workpiece-interface. For example,the pretreatments may level one or more regions of theworkpiece-interface and/or may provide desirable metallurgicalproperties across one or more regions of the workpiece-interface. Thepretreatment may also improve bonding between the workpiece and anextension segment additively printed on the workpiece followingpretreatment. Additionally, the pretreatment may improve the precisionand/or accuracy with which an extension segment may be additivelyprinted on a workpiece. Exemplary pretreatments may includeadditive-leveling, melt-leveling, and/or heat-conditioning. In someembodiments, a workpiece-interface may be leveled using a pretreatmentthat includes additive-leveling and/or melt-leveling. Additionally, orin the alternative, a pretreatment may remove oxidation, contaminants,debris, and/or subtractive modification artifacts (e.g., grooves,scratches, burrs, etc.) from the workpiece-interface 120.

In some embodiments, the present disclosure provides systems and methodsof determining or generating a CAD model that includes a model of one ormore extension segments, such as an extension segment-CAD model, thatconform to the location and shape of one or more correspondingworkpieces upon which the extension segments are to be additivelyprinted. Such an extension segment-CAD model may be utilized to generateprint commands for an additive manufacturing machine, allowing theadditive manufacturing machine to additively print extension segmentsonto workpiece-interfaces with sufficient precision or accuracy toprovide near net shape components.

The present disclosure provides for determining and/or generating anextension segment CAD model, for example, from a library-CAD model thatincludes a nominal model of one or more nominal workpieces, components,or extension segments. The library-CAD model may be selected from alibrary of CAD models based at least in part on a digital representationof a field of view of one or more workpiece-interfaces obtained from thevision system. A nominal model-interface traversing a nominal model maybe determined in a library-CAD model, and a model of an extensionsegment may be selected and/or generated based at least in part on acomparison of the nominal model-interface to a digital representation ofa workpiece-interface. A model of one or more extension segments may beoutput to an extension segment-CAD model and print commands for theadditive manufacturing machine may be generated using the extensionsegment-CAD model.

The present disclosure additionally provides for determining and/orgenerating a pretreatment-CAD model. By way of example, apretreatment-CAD model may be determined or generated from an extensionsegment-CAD model and/or from a library-CAD model that includes anominal model of one or more nominal workpieces, components, orextension segments. A model of a pretreatment region may be selectedand/or generated based at least in part on a comparison of a nominalmodel-interface to a digital representation of a workpiece-interface. Amodel of one or more pretreatment regions may be output to apretreatment-CAD model and pretreatment commands for pretreatingworkpiece-interfaces may be generated using the pretreatment-CAD model.

In some embodiments, generating a model of an extension segment mayinclude extracting the nominal model-interface from the nominal model,transforming the nominal model-interface based at least in part on thecomparison to the digital representation of the workpiece-interface,and/or extending the transformed model-interface so as to provide themodel of the extension segment. Additionally, or in the alternative, amodel of an extension segment may be generated from a three-dimensionalportion of a nominal model, which may include transforming suchthree-dimensional portion so as to provide a model of an extensionsegment conforming to the digital representation of theworkpiece-interface. Similarly, generating a model of a pretreatmentregion may include extracting a nominal model-interface from the nominalmodel, transforming the nominal model-interface based at least in parton a comparison to the digital representation of theworkpiece-interface, and/or extending the transformed model-interface soas to provide the model of the pretreatment region. Additionally, or inthe alternative, a model of a pretreatment region may be generated froma three-dimensional portion of a nominal model, which may includetransforming such three-dimensional portion so as to provide a model ofa pretreatment region conforming to the digital representation of theworkpiece-interface.

The present disclosure also provides for systems and methods ofperforming calibration adjustments so as to prevent or mitigatediscrepancies, biases, misalignments, calibration errors, or the likewhich may otherwise arise from time to time as between one or moreaspects of the additive manufacturing system. Such calibrationadjustments may be configured to address potential discrepancies,biases, misalignments, calibration errors, or the like between a visionsystem and an additive manufacturing machine, between a vision systemand one or more CAD models generated, or between one or more CAD modelsand an additive manufacturing machine, as well as combinations of these.

When additively printing an extension segment on a workpiece-interface,misalignment between the workpiece and the extension segment may resultin a failed build or a defective component. Previous additivemanufacturing system may exhibit systematic bias in the mapping betweenthe scan path coordinates and the coordinates of a CAD model. Suchsystematic bias may cause additively printed components to be shiftedglobally, which may have been of little consequence for previousadditive manufacturing systems. However, the present disclosure providesfor near net shape components, such that the extension segment conformsto the location and shape of the workpiece-interface of the workpiece.To provide such near net shape components, not only is the precision ofthe additive manufacturing tool of importance, but it is also ofimportance that the location and shape of the workpieces andcorresponding extension segments be accurately and precisely alignedwith one another.

In some embodiments, the additive material used for the extensionsegments may differ from the material of the workpieces. Differences inmaterial may provide for different properties or performancecharacteristics of the extension segments relative to the workpieces,including enhanced wear resistance, improved hardness, strength, and/orductility. New or unused components may be additively manufactured orupgraded in accordance with the present disclosure so as to provide anextension segment with a material that differs from that of theworkpiece. For example, airfoils such as compressor blades or turbineblades may be upgraded with blade tips formed of a superior performingmaterial. Likewise, damaged or worn components may be repaired orrebuild using a material that differs from that of the workpiece, forexample, using a superior performing material. Further, a material usedin connection with a pretreatment may differ from a material used for anextension segment and/or a material included in the workpiece.

Exemplary embodiments of the present disclosure will now be described infurther detail. Exemplary embodiments of an additive manufacturingsystem 100 are shown in FIGS. 1A and 1B. An exemplary additivemanufacturing system 100 includes a vision system 102, an additivemanufacturing machine 104, and a control system 106 operably configuredto control the vision system 102 and/or the additive manufacturingmachine 104. The vision system 102 and the additive manufacturingmachine 104 may be provided as a single, integrated unit or as separatestand-alone units. The vision system 102 and the additive manufacturingmachine 104 may be operably coupled with one another via a communicationinterface utilizing wired or wireless communication lines, which mayprovide a direct connection between the vision system 102 and theadditive manufacturing machine 104. The control system 106 may includeone or more control systems 106. For example, a single control system106 may be operably configured to control operations of the visionsystem 102 and the additive manufacturing machine 104, or separatecontrol systems 106 may be operably configured to respectively controlthe vision system 102 and the additive manufacturing machine 104. Acontrol system 106 may be realized as part of the vision system 102, aspart of the additive manufacturing machine 104, and/or as a stand-aloneunit provided separately from the vision system 102 and/or the additivemanufacturing machine 104. A control system 106 may be operably coupledwith the vision system 102 and/or the additive manufacturing machine 104via a communication interface utilizing wired or wireless communicationlines, which may provide a direct connection between the control system106 and the vision system 102 and/or between the control system 106 andthe additive manufacturing machine 104. An exemplary additivemanufacturing system 100 may optionally include a user interface 108and/or a management system 110.

In some embodiments, a first control system 106 may determine anextension segment-CAD model, generate one or more print commands basedat least in part on the extension segment-CAD model, and/or transmit theone or more print commands to a second control system 106, and thesecond control system 106 may cause the additive manufacturing machine104 to additively print the extension segments based at least in part onthe print commands. The first control system 106 may be realized as partof a vision system 102, and/or the second control system 106 may berealized as part of the additive manufacturing machine 104.Alternatively, or in addition, the first control system 106 and/or thesecond control system 106 may be realized stand-alone units separatefrom the vision system 102 and/or the additive manufacturing machine104.

In some embodiments, a first control system 106 may determine andtransmit an extension segment-CAD model to a second control system 106,the second control system 106 may slice the extension segment-CAD modelso as to generate one or more print commands and concurrently orsubsequently transmit the one or more print commands to a third controlsystem 106, and the third control system may cause the additivemanufacturing machine 104 to additively print the extension segmentsbased at least in part on the one or more print commands. The firstcontrol system 106 may be realized as part of a vision system 102, thesecond control system 106 may be realized as a stand-alone unit, and thethird control system 106 may be realized as part of the additivemanufacturing machine 104. Alternatively, or in addition, the firstcontrol system 106 and/or the second control system 106 may be realizedas stand-alone units separate from the vision system 102 and/or theadditive manufacturing machine 104.

In some embodiments, a control system 106 may determine apretreatment-CAD model and/or generate one or more pretreatment commandsbased at least in part on the pretreatment-CAD model. For example, afirst control system 106 may determine the pretreatment-CAD model and/ortransmit the pretreatment-CAD model to a second control system 106, andthe second control system 106 may generate one or more pretreatmentcommands based at least in part on the pretreatment-CAD model, and thesecond control system 106 may also cause the additive manufacturingmachine 104 to subject the extension segments to a pretreatment based atleast in part on the pretreatment commands. As another example, thefirst control system 106 may determine and transmit a pretreatment-CADmodel to a second control system 106, the second control system 106 maygenerate one or more pretreatment commands based at least in part on thepretreatment-CAD model and concurrently or subsequently transmit the oneor more pretreatment commands to a third control system 106, and thethird control system may cause the additive manufacturing machine 104 tosubject the extension segments to a pretreatment based at least in parton the pretreatment commands. The first control system 106 may berealized as part of a vision system 102, the second control system 106may be realized as a stand-alone unit, and the third control system 106may be realized as part of the additive manufacturing machine 104.Alternatively, or in addition, the first control system 106 and/or thesecond control system 106 may be realized as stand-alone units separatefrom the vision system 102 and/or the additive manufacturing machine104.

The vision system 102 may include any suitable camera or cameras 112 orother machine vision device that may be operably configured to obtainimage data that includes a digital representation of one or more fieldsof view 114. Such a digital representation may sometimes be referred toas a digital image or an image; however, it will be appreciated that thepresent disclosure may be practiced without rendering such a digitalrepresentation in human-visible form. Nevertheless, in some embodiments,a human-visible image corresponding to a field of view 114 may bedisplayed on the user interface 108 based at least in part on such adigital representation of one or more fields of view 114.

The vision system 102 allows the additive manufacturing system 100 toobtain information pertaining to one or more workpieces 116 onto which apretreatment may be applied and/or onto which one or more extensionsegments may be respectively additively printed. In particular, thevision system 102 allows the one or more workpieces 116 to be locatedand defined so that the additive manufacturing machine 104 may beinstructed to pretreat the workpiece-interfaces 120 of one or moreworkpieces with suitably high accuracy and precision and/or to print oneor more extension segments on a corresponding one or more workpieces 116with suitably high accuracy and precision. The one or more workpieces116 may be secured to a build plate 118 with a workpiece-interface (e.g.a top surface) 120 of the respective workpieces 116 aligned to a buildplane 122.

The one or more cameras 112 of the vision system 102 may be configuredto obtain two-dimensional or three-dimensional image data, including atwo-dimensional digital representation of a field of view 114 and/or athree-dimensional digital representation of a field of view 114.Alignment of the workpiece-interfaces 120 with the build plane 122allows the one or more cameras 112 to obtain higher quality images. Forexample, the one or more cameras 112 may have a focal length adjusted oradjustable to the build plane 122. With the workpiece-interface 120 ofone or more workpieces 116 aligned to the build plane 122, the one ormore cameras may readily obtain digital images of theworkpiece-interfaces 120. The one or more cameras 112 may include afield of view 114 that that encompasses all or a portion of the one ormore workpieces 116 secured to the build plate 118. For example, asingle field of view 114 may be wide enough to encompass a plurality ofworkpieces 116, such as each of a plurality of workpieces secured to abuild plate 118. Alternatively, a field of view 114 may more narrowlyfocus on an individual workpiece 116 such that digital representationsof respective workpieces 116 are obtained separately. It will beappreciated that separately obtained digital images may be stitchedtogether to obtain a digital representation of a plurality of workpieces116. In some embodiments, the camera 112 may include a collimated lensconfigured to provide a flat focal plane, such that workpieces orportions thereof located towards the periphery of the field of view 114are not distorted. Additionally, or in the alternative, the visionsystem 102 may utilize a distortion correction algorithm to address anysuch distortion.

Image data obtained by the vision system 102, including a digitalrepresentation of one or more workpieces 116 may be transmitted to thecontrol system 106. The control system 106 may be configured todetermine a workpiece-interface 120 of each of a plurality of workpieces116 from one or more digital representations of one or more fields ofview 114 having been captured by the vision system 102, and thendetermine one or more coordinates of the workpiece-interface 120 ofrespective ones of the plurality of workpieces 116. Based on the one ormore digital representations, the control system 106 may generate one ormore print commands and/or one or more pretreatment commands, which maybe transmitted to an additive manufacturing machine 104 such that theadditive manufacturing machine 104 may additively print a plurality ofextension segments on respective ones of the plurality of workpieces 116and/or subject the plurality of workpieces 116 to a pretreatment priorto additively printing the plurality of extension segments thereon. Theone or more print commands may be configured to additively print aplurality of extension segments with each respective one of theplurality of extension segments being located on the workpiece-interface120 of a corresponding workpiece 116. The pretreatment commands may beconfigured to expose the workpiece-interfaces 120 of the workpieces 116to a pretreatment so as to prepare the workpiece-interfaces 120 foradditively printing extension segments thereon.

The additive manufacturing machine 104 may utilize any desired additivemanufacturing technology. In an exemplary embodiment, the additivemanufacturing machine may utilize a powder bed fusion (PBF) technology,such as direct metal laser melting (DMLM), electron beam melting (EBM),selective laser melting (SLM), directed metal laser sintering (DMLS), orselective laser sintering (SLS). The additive manufacturing machine 104may include any such additive manufacturing technology, or any othersuitable additive manufacturing technology may also be used. By way ofexample, using a powder bed fusion technology, respective ones of aplurality of extension segments may be additively printed oncorresponding respective ones of a plurality of workpieces 116 in alayer-by-layer manner by melting or fusing a layer of powder material tothe workpiece-interface 120. In some embodiments, a component may beadditively printed by melting or fusing a single layer of poweredmaterial to the workpiece-interface 120. Additionally, or in thealternative, subsequent layers of powder material may be sequentiallymelted or fused to one another. The pretreatment may be applied usingthe same additive manufacturing machine 104 utilized to additively printthe extension segments.

Still referring to FIGS. 1A and 1B, an exemplary additive manufacturingmachine 104 includes a powder supply chamber 124 that contains a supplyof powder 126, and a build chamber 128. A build plate 118 having one ormore workpieces 116 secured thereto may be positioned in the buildchamber 128, where the workpieces 116 may be additively printed in alayer-by-layer manner. The powder supply chamber 124 includes a powderpiston 130 which elevates a powder floor 132 during operation of thesystem 100. As the powder floor 132 elevates, a portion of the powder126 is forced out of the powder supply chamber 124.

A recoater 134, such as a roller or a blade, pushes some of the powder126 across a work surface 136 and onto a build platform 138. The buildplate 118 may be secured to the build platform 138 with a chuck system140 in a manner configured to position the build plate 118 on the buildplatform 138 and/or within the build chamber 128 with sufficiently highaccuracy and precision. The workpieces 116 may be secured to the buildplate 118 prior to securing the build plate 118 to the build platform138. The recoater 134 fills the build chamber 128 with powder 126 andthen sequentially distributes thin layers of powder 126 across a buildplane 122 near the top of the workpieces 116 to additively printsequential layers of the workpieces 116. For example, the thin layers ofpowder 126 may be about 10 to 100 microns thick, such as about 20 to 80μm thick, such as about 40 to 60 μm thick, or such as about 20 to 50 μmthick, or such as about 10 to 30 μm thick. The build plane 122represents a plane corresponding to a next layer of the workpieces 116to be formed from the powder 126.

To form a layer of an extension segment on the workpiece 116 (e.g., aninterface layer or a subsequent layer), an energy source 142 directs anenergy beam 144 such as a laser or an electron beam onto the thin layerof powder 126 along the build plane 122 to melt or fuse the powder 126to the top of the workpieces 116 (e.g., to melt or fuse a layer to theworkpiece-interfaces 120 and/or melt or fuse subsequent layers thereto).A scanner 146 controls the path of the energy beam 144 so as to melt orfuse the portions of the powder 126 layer that are to become melted orfused to the workpieces 116. Typically, with a DMLM, EBM, or SLM system,the powder 126 is fully melted, with respective layers being melted orre-melted with respective passes of the energy beam 144. Conversely,with DMLS, or SLS systems, layers of powder 126 are sintered, fusingparticles of powder 126 with one another generally without reaching themelting point of the powder 126. After a layer of powder 126 is meltedor fused to the workpieces 116, a build piston 148 gradually lowers thebuild platform 138 by an increment, defining a next build plane 122 fora next layer of powder 126 and the recoater 134 to distributes the nextlayer of powder 126 across the build plane 122. Sequential layers ofpowder 126 may be melted or fused to the workpieces 116 in this manneruntil the additive printing process is complete.

The extension segments may be additively printed on theworkpiece-interfaces 120 of respective workpieces 116 at an energydensity selected so as to provide a proper bond between theworkpiece-interface 120 and the layers of melted or fused powder 126that form the extension segment 206. As used herein, the term “energydensity” refers to the volumetric energy density E, which may have unitsof Joules per cubic millimeter (J/mm³) and may be described according toequation (1) as follows:

$\begin{matrix}{{E = {\frac{P}{v \cdot h \cdot t}k_{o}k_{r}}},} & (1)\end{matrix}$where P is the power of the energy beam 144 in watts (W), v is the scanspeed of the energy beam 144 in millimeters per second (mm/s), h is thehatch spacing between adjacent scan path passes in millimeters (mm), tis the incremental layer thickness in millimeters (mm) as indicated bythe incremental amount of lowering of the build platform 138 betweensequential layers of powder applied across the build plane 122, k_(o) isan overlap constant corresponding to the amount of overlap betweenadjacent scan path passes, and k_(r) is a remelt constant correspondingto the amount of remelt between adjacent layers.

Variations of the parameters affecting energy density may greatlyinfluence additive printing quality, and in some embodiments the energydensity and/or various parameters thereof that may be suitable forforming an original component may be unsuitable for additively printingan extension segment on a pre-existing workpiece 116. For example, theenergy density used to additively print an extension segment on apre-existing workpiece 116 may be substantially greater than a typicalenergy density used to additively print an original component. Theenergy density may be substantially greater, for example, to achieve adesired porosity of the extension segment. The porosity may be describedwith reference to relative density according to equation (2) as follows:

$\begin{matrix}{{\rho_{rel} = \frac{\rho^{*}}{\rho_{s}}},} & (2)\end{matrix}$where ρ* is the density of the additively printed material, and ρ_(s) isthe density of the raw material used.

Post-processing such as heat treatment applied to the workpiece 116and/or exposure to high temperature operating conditions may modify therelative density of the workpiece 116 (e.g., through grain growth,precipitates, twinning, etc.) from that which existed when the workpiece116 was originally formed. The energy density of the energy beam 144 maybe selected so as to provide an extension segment having a relativedensity, crystal structure, or other properties corresponding to that ofthe workpiece 116, such as after accounting for effects of suchpost-processing or operating conditions on the workpiece 116. Forexample, it may be undesirable to subject a component formed byadditively printing the extension segment on a workpiece 116 to certainpost processing such as heat treatment because the workpiece 116 mayhave already been subjected to such post processing. As a result, it maybe desirable for the additive printing process to provide extensionsegments having a desired relative density, crystalline structure, andso forth without contribution from post-processing such as heattreatment.

In some embodiments, the relative density of an extension segment may beselected so as to substantially match the relative density of aworkpiece 116 and/or so as to be equal to or greater than the relativedensity of the workpiece 116. In some embodiments the relative densityof the extension segment may be substantially greater than the relativedensity of the workpiece. By way of example, an extension segment mayhave a relative density of from about 0.950 to 0.9999, such as from0.970 to 0.9999, such as from 0.990 to 0.9999, such as from 0.997 to0.9999, such as at least 0.990, such as at least 0.995, such as at least0.997, such as at least 0.998, such as at least 0.9990, such as at least0.9995, such as at least 0.9997, such as at least 0.9998, such as atleast 0.9999. In some embodiments, an extension segment may exhibit afirst relative density and a workpiece may exhibit a second relativedensity, in which the first relative density exceeds the second relativedensity by from about 10 to about 100 thousandths, such as from about 10to about 80 thousandths, such as from about 10 to about 60 thousandths,such as from about 10 to about 40 thousandths, such as from about 10 toabout 20 thousandths, such as from about 20 to about 80 thousandths,such as from about 40 to about 80 thousandths, such as from about 60 toabout 100 thousandths.

To achieve such a relative density, the energy density used toadditively print an extension segment on a pre-existing workpiece 116may be substantially greater than a typical energy density values. Forexample, whereas typical energy density values may range from about 20J/mm³ to about 70 J/mm³, exemplary energy density values used toadditively print an extension segment on a workpiece 116 may range fromabout 20 J/mm³ to about 200 J/mm³, such as from about 70 J/mm³ to about200 J/mm³, such as from about 80 J/mm³ to about 200 J/mm³, such as fromabout 100 J/mm³ to about 160 J/mm, such as from about 120 J/mm³ to about140 J/mm³, such as from about 140 J/mm³ to about 180 J/mm³, such as fromabout 160 J/mm³ to about 200 J/mm³ Such energy density may be at leastabout 20 J/mm³, such as at least about 50 J/mm³, such as at least about70 J/mm, such as at least about 100 J/mm³, such as at least about 120J/mm³, such as at least about 140 J/mm³, such as at least about 160J/mm³. Such energy density may be less than about 200 J/mm³, such asless than about 160 J/mm³, such as less than about 140 J/mm³, such asless than about 120 J/mm³. For example, in some embodiments, theforegoing energy density values may be achieved when the product ofk_(o) and k_(r) is about 1.0, such as from about 0.2 to about 2.0, suchas from about 0.5 to about 1.5, or such as from about 0.8 to about 1.2.

In some embodiments, the workpieces 116 (e.g., the workpiece-interfaces120) may be subjected to a pretreatment, which may be performed withand/or without powder 126 applied to the workpiece-interface 120. Toperform a pretreatment, an energy source 142 directs an energy beam 144such as a laser or an electron beam onto the workpiece-interface 120and/or a thin layer of powder 126 along the build plane 122. Thepretreatment may be performed at an energy density selected so as toprovide the desired effect of the pretreatment, such asadditive-leveling, melt-leveling, and/or heat conditioning. When thepretreatment is performed with powder 126 applied to theworkpiece-interface 120, the energy density may be described accordingto equation (1) above. When the pretreatment is performed without powder126, such as in the case of a melt-leveling pretreatment and/or aheat-conditioning pretreatment, the energy density may be describedaccording to equation (1), where t equals 1. Variations of theparameters affecting energy density may also greatly influence thecharacter and effect of the pretreatment, and in some embodiments theenergy density and/or various parameters thereof that may be suitablefor forming an original component or for printing an extension segmenton a pre-existing workpiece may be unsuitable for pretreatment. Forexample, in some embodiments the energy density used to pretreat aworkpiece-interface 120 may be substantially lower than a typical energydensity used to additively print an original component and/or anextension segment. For example, some heat-conditioning pretreatments maybe performed at an energy density that does not generate a melt pool. Insome embodiments, a workpiece-interface may be pretreated using a firstenergy density that is from about 10% to about 100% of a second energydensity used to additively print an extension segment on theworkpiece-interface, such as a first energy density that is from about10% to about 90% of the second energy density, such as a first energydensity that is from about 10% to about 70% of the second energydensity, such as from about 20% to about 50% of the second energydensity, such as from about 40% to about 80% of the second energydensity, or such as from about 60% to about 90% of the second energydensity. Such first energy density and/or such second energy density maybe utilized for all or a portion of the respective pretreatment oradditive-printing operation.

However, in other embodiments an energy density used to pretreat aworkpiece-interface may be comparable to an energy density used toadditively print an extension segment on a workpiece 116. For example,in some embodiments, an additive-leveling pretreatments and/or amelt-leveling pretreatments may be performed at an energy densitycomparable to an energy density used to additively print an extensionsegment on the pretreated workpiece-interface. However, in otherembodiments, an additive-leveling pretreatments and/or a melt-levelingpretreatments may be performed at an energy density that differssignificantly from an energy density used to print an extension segmenton the pretreated workpiece-interface. For example, an energy densityused to perform an additive-leveling pretreatment and/or a melt-levelingpretreatment may be selected so as to provide a desired relative densityat or near the workpiece-interface of the workpiece. For example, anenergy density may be selected for the additive-leveling pretreatmentand/or the melt-leveling pretreatment so as to provide a graduatedrelative density that transitions from a first relative density of theworkpiece to a second relative density of the workpiece-interface.

In still further embodiments, the energy density selected for apretreatment such as an additive-leveling pretreatment and/or amelt-leveling pretreatment may be significantly greater than the energydensity selected for additively printing an extension segment on thepretreated workpiece-interface. For example, some aberrant features maybe more effectively remediated using an energy density that issignificantly higher than suitable energy density values foradditively-printing an extension segment on the pretreatedworkpiece-interface. In some embodiments, a workpiece-interface may bepretreated using a first energy density that is from about 100% to about300% of a second energy density used to additively print an extensionsegment on the workpiece-interface, such as a first energy density thatis from about 110% to about 300% of the second energy density, such as afirst energy density that is from about 110% to about 200% of the secondenergy density, such as from about 110% to about 150% of the secondenergy density, such as from about 150% to about 200% of the secondenergy density, or such as from about 200% to about 300% of the secondenergy density. Such first energy density and/or such second energydensity may be utilized for all or a portion of the respectivepretreatment or additive-printing operation.

In various embodiments, the pretreatment may be performed without powder126 applied across the workpiece-interface 120, while in otherembodiments a thin layer of powder 126 may be applied across all or aportion of the workpiece-interface 120. The energy beam 144 may follow atool path in a manner generally similar to a scan path followed whenadditively printing on a workpiece-interface; however, the energy beam144 may exhibit a different characteristic and/or may achieve adifferent effect as compared to additively printing depending on theobjectives of the pretreatment.

Regardless of whether or not there is powder 126 applied across theworkpiece-interface 120, the energy beam may generate a melt pool pathand/or a heat treatment path across the workpiece-interface 120. Thepretreatment may prepare the workpiece-interface 120 for subsequentlyadditively printing thereon, for example, by remediating aberrantfeatures of the workpiece 116 and/or of the workpiece-interface 120and/or by enhancing one or more features of the workpiece 116 and/or ofthe workpiece-interface 120 in preparation for additively printing anextension segment on the workpiece-interface 120. A workpiece 116 and/ora workpiece-interface 120 that includes one or more aberrant featuresmay sometimes be referred to respectively as an aberrant workpiece 116or an aberrant workpiece-interface 120. By way of example, an aberrantworkpiece-interface 120 may be at least partially askew relative to thebuild plane 122. Additionally, or in the alternative, an aberrantworkpiece-interface 120 may include one or more regions that differ inelevation relative to the build plane 122 and/or relative to oneanother, and/or that are at least partially askew relative to oneanother. As further example, an aberrant workpiece 116 orworkpiece-interface 120 may include oxidation, contaminants, debris,subtractive modification artifacts (e.g., grooves, scratches, burrs,etc.), incongruent or undesirable grain structures and/or grain sizes,dislocations, microcracks, and/or voids.

The pretreatment may remediate such aberrant features and/or enhance oneor more features. For example, in some embodiments, the pretreatment mayby level the workpiece-interface 120 through melt-leveling and/oradditive-leveling. Additionally, or in the alternative, the pretreatmentmay remove oxidation, contaminants, debris, and/or subtractivemodification artifacts (e.g., grooves, scratches, burrs, etc.) from theworkpiece-interface 120. The pretreatment may include melt-levelingand/or additive-leveling. Additionally, or in the alternative, thepretreatment may include heat-conditioning.

A pretreatment that includes melt-leveling pretreatment may includeusing the energy beam to generate a melt pool across at least a portionof the workpiece-interface 120. A pretreatment that includesadditive-leveling may include applying powder 126 across at least aportion of the workpiece-interface 120 and melting or fusing the powder126 to at least a portion of the workpiece-interface, such as at one ormore regions of the workpiece-interface having a lower elevationrelative to the build plane 122 and/or relative to one or more otherregions of the workpiece-interface. It will be appreciated that apretreatment may include additive-leveling and/or melt-leveling,individually or in combination. For example, a first region of theworkpiece-interface 120 may be subjected to melt-leveling and a secondregion of the workpiece-interface 120 may be subjected to additiveleveling. Additionally, or in the alternative, at least a portion of aworkpiece interface 120 may be subjected to melt leveling followed byadditive-leveling.

A pretreatment that includes heat-conditioning may include generating aheat-treatment scan path and/or a melt-pool scan path across at least aportion of the workpiece-interface. The heat-treatment scan path and/ora melt-pool scan path heat-conditioning pretreatment may includemodifying the grain structure of the workpiece 116 at or near theworkpiece-interface 120, for example, remediating aberrant grainstructures and/or grain sizes, dislocations, microcracks, and/or voids.Heat-conditioning may also include enhancing grain structures and/orgrain sizes, for example, providing a more uniform grain structureand/or a grain structure with enhanced hardness, tensile strength and/orductility properties, providing a smaller or larger grain size, changinggrain size distribution, and/or providing a grain size or distributionwith enhanced hardness, tensile strength, and/or ductility properties.Such a heat-conditioning pretreatment may be provided concurrently withor as a result of melt-leveling or additive-leveling. Additionally, orin the alternative, a heat-conditioning pretreatment may be providedseparately from a melt-leveling or additive-leveling pretreatment. Apretreatment may include heat-conditioning individually or incombination with melt-leveling and/or additive-leveling.

A pretreatment that includes additive-leveling may include applying oneor more layers of powder 126 across the workpiece-interface 120 andusing the energy beam 144 to melt or fuse the powder 126 to the top ofthe workpieces 116 (e.g., to melt or fuse a layer to theworkpiece-interfaces 120 and/or melt or fuse subsequent layers thereto)similarly to additively printing an extension segment 206 on theworkpiece 116. However, the characteristic and/or the effect of powder126 melted or fused to a workpiece 116 as part of a pretreatment may bedistinguished from the characteristic and/or the effect of powder 126melted or fused to a workpiece 116 as part of additively printing anextension segment 206 on the workpiece 116. For example, in someembodiments, the powder 126 used for the pretreatment may have adifferent composition from the powder 126 used for additively printingan extension segment 206. Additionally, or in the alternative, in someembodiments, the energy beam 144 may provide a higher or lower energydensity during the pretreatment relative to the energy density used whenadditively printing the extension segment 206. The one or more powder126 layers melted or fused to the workpiece-interface during thepretreatment may be provided so as to additively-level theworkpiece-interface and/or to provide desirable metallurgical propertiesacross the workpiece-interface 120. The one or more powder 126 layersmay be applied to all or a portion of a workpiece-interface 120, and apretreatment command may be configured to melt or fuse the powder 126 toall or a portion of the workpiece-interface 120. Such characteristicsand/or effects of pretreatment may improve bonding between the workpiece116 and an extension segment 206 additively printed on the workpiecefollowing pretreatment. Additionally, or in the alternative, suchcharacteristics and/or effects of pretreatment may improve the precisionand/or accuracy with which an extension segment 202 may be additivelyprinted on a workpiece 116.

In some embodiments, when an aberrant workpiece-interface 120 exhibitsskewness and/or differing elevations relative to the build plane 122and/or relative to various regions, the skewness or differing elevationmay range from about 1 micrometer (μm) to about 500 μm. For example, afirst region of the workpiece-interface 120 may exhibit skewness and/ora differing elevation relative to the build plane 122 and/or relative toa second region of the workpiece-interface 120, such as from about 1micrometer (μm) to about 500 μm, such as from about 25 μm to about 400μm, such as from about 50 μm to about 250 μm, or such as from about 75μm to about 150 μm, such as at least 10 μm, such as at least 25 μm, suchas at least 50 μm, such as at least 75 μm, such as at least 150 μm, suchas at least 250 μm, or such as at least 400 μm. Regardless of whetherthe pretreatment includes additive-leveling or melt-leveling, thepretreatment may at least partially level the workpiece-interface 120,reducing such skewness and/or differences in elevation. For example,skewness and/or a difference in elevation of an aberrantworkpiece-interface 120 may be reduced by from 50% to 100%, such as from75% to 100%, such as from 90% to 100%. A pretreatment may level theworkpiece-interface 120, for example, as between a first region of theworkpiece-interface 120 to a second region of the workpiece-interface120, to from about 1 μm to about 75 μm, such as from about 1 μm to about50 μm, such as from about 1 μm to about 25 μm, such as from about 1 μmto about 10 μm.

Still referring to FIGS. 1A and 1B, to perform a pretreatment, a scanner146 controls the path of the energy beam 144 so as to melt or heat atleast a portion of the workpiece-interface 120 and/or to melt or fuse atleast portions of the powder 126 layer to the workpiece-interface 120.In some embodiments, after a layer of powder 126 is melted or fused tothe workpieces 116, a build piston 148 gradually lowers the buildplatform 138 by an increment, defining a next build plane 122 for a nextlayer of powder 126, and the recoater 134 may then distribute the nextlayer of powder 126 across the next build plane 122. Sequential layersof powder 126 may be melted or fused to the workpieces 116 in thismanner until the pretreatment process is complete.

Now referring to FIGS. 2A and 2B, an exemplary workpiece-assembly 200that includes a plurality of workpieces 116 secured to a build plate 118is shown. The build plate 118 may be configured to align the workpieces116 to respective registration points 202. The registration points 202may be mapped to a coordinate system. FIG. 2A shows a workpiece-assembly200 that includes a plurality of workpieces 116 secured to a build plate118. The arrangement depicted in FIG. 2A reflects a point in time priorto additively printing extension segments 206 onto theworkpiece-interfaces 120. FIG. 2B shows the workpiece-assembly 200 ofFIG. 2A but reflecting a point in time after an additive printingprocess. As shown in FIG. 2B, a plurality of components 204 are securedto the build plate 118, which were formed during the additive printingprocess by additively printing respective ones of a plurality ofextension segments 206 onto respective ones of the plurality ofworkpieces 116.

The build plate 118 and/or workpiece-assembly 200 shown in FIGS. 2A and2B may be used to facilitate additively printing an extension segment206 on a workpiece 116, including additively printing respective ones ofa plurality of extension segments 206 on respective ones of a pluralityof workpieces 116 as part of a single build. In some embodiments, abuild plate 118 may be configured to align the workpieces 116 torespective registration points 202 so as to facilitate image capture bythe vision system 102, so as to facilitate alignment of CAD models withthe workpieces 116 (e.g., so that extension segments 206 as defined by aCAD model may be properly additively printed on the workpieces 116),and/or so as to facilitate operability of the additive manufacturingmachine 104.

The workpiece-assembly 200 shown in FIGS. 2A and 2B may hold any numberof workpieces 116. As one example, the workpiece-assembly 200 shown mayhold up to 20 workpieces 116. As another example, a workpiece-assembly200 may be configured to hold from 2 to 100 workpieces 116, or more,such as from 2 to 20 workpieces 116, such as from 10 to 20 workpieces116, such as from 20 to 60 workpieces 116, such as from 25 to 75workpieces 116, such as from 40 to 50 workpieces 116, such as from 50 to100 workpieces 116, such as from 5 to 75 workpieces 116, such as from 75to 100 workpieces 116, such as at least 2 workpieces 116, such as atleast 10 workpieces 116, such as at least 20 workpieces 116, such as atleast 40 workpieces 116, such as at least 60 workpieces 116, or such asat least 80 workpieces 116.

In some embodiments, for example, when the workpieces 116 are airfoilssuch as compressor blades or turbine blades of a turbomachine, theworkpiece-assembly 200 may be configured to hold a number of blades thatcorresponds to the number of blades in one or more stages of thecompressor and/or turbine, as applicable. In this way, all of the bladesof a given one or more stages of a turbine and/or compressor may be kepttogether and extension segments 206 may be additively printed thereon inone single build. It will be appreciated that the workpiece-assembly 200and build plate 118 reflect one exemplary embodiment, which is providedby way of example and not to be limiting. Various other embodiments of aworkpiece-assembly 200 and/or build plate 118 are contemplated which mayalso allow for the workpieces 116 to be secured with suitablepositioning and alignment, all of which are within the spirit and scopeof the present disclosure.

The exemplary workpiece-assembly 200 shown in FIGS. 2A and 2B includes abuild plate 118 with one or more workpiece bays 208 disposed therein.Each of the one or more workpiece bays 208 may include one or moreworkpiece docks 210. The one or more workpiece bays 208 may additionallyinclude one or more clamping mechanisms 212 which operate to secure oneor more workpieces 116 to the build plate 118. The one or more workpiecedocks 210 may be configured to receive one or more workpiece shoes 214,and the one or more workpiece shoes 214 may be respectively configuredto receive a workpiece 116. The one or more clamping mechanisms 212 maybe configured to clamp the workpiece shoes 214 in position within thecorresponding workpiece docks 210.

A workpiece dock 210 and/or a workpiece shoe 214 may include one or morebiasing members (not shown) configured to exert a biasing force (e.g.,an upward or vertical biasing force) between the workpiece shoe 214 andthe build plate 118 such as the bottom of the workpiece dock 210. Thebiasing members may include one or more springs, one or more magnetpairs (e.g. permanent magnets or electromagnets), one or morepiezoelectric actuator, or the like operable to exert such a biasingforce. The biasing force exerted by the biasing members biases theworkpiece shoe 214 so as to allow the workpiece-interfaces 120 (e.g.,the top surfaces of the workpieces 116) to be aligned with one another.By way of example, an alignment plate (not shown) may be placed on topof the workpieces 116 so as to partially compress the biasing membersand bring the workpiece-interfaces 120 (e.g., the top surfaces of theworkpieces 116) into alignment with one another. In some embodiments,elevating blocks (not shown) may be placed between the build plate 118and the alignment plate (not shown) to assist in positioning thealignment plate on top of the workpieces 116 at a desired height. Withthe workpiece-interfaces 120 aligned with one another, the clampingmechanism 212 may be tightened so as to secure the workpieces 116 to thebuild plate 118.

As shown in FIGS. 3A and 3B, a misalignment of workpieces 116 from thebuild plane 122 may introduce printing failures. FIG. 3A shows aplurality of workpieces 116, including a first workpiece 300 situated inalignment with the build plane 122, a second workpiece 302 situatedbelow the build plane 122, and a third workpiece 304 situated above thebuild plane 122. When the recoater 134 distributes powder 126 across thebuild plane 122, the first workpiece 300 would generally be expected toreceive an appropriately thick layer of powder 126 across the topportion thereof. By contrast, the second workpiece 302 and the thirdworkpiece 304 illustrate misalignments from the build plane 122 whichmay likely cause printing failures. For example, the second workpiece302 may exhibit printing failures attributable to an overly thick layer306 of powder 126, such as insufficient bonding of the powder 126 layerto the second workpiece 302. Such insufficient bonding may be caused byincomplete melting of the powder 126 or the top layer (e.g., theworkpiece-interface 120) of the second workpiece 302, as well as voidsformed from gasses trapped within the layer that with adequate meltinggenerally would be eliminated. As another example, the third workpiece304 may exhibit printing failures attributable to the surface 308 of thethird workpiece 304 protruding above the build plane 122, such that therecoater 134 may skip over the protruding surface 308 of the thirdworkpiece 304 and/or such that the recoater 134 may become obstructed bythe third workpiece, damaging the recoater 134 or preventing therecoater 134 from moving past the protruding surface 308.

In some embodiments, even if a mis-aligned workpiece 116 does not causea total printing failure such as obstructing the recoater 134, themisalignment may cause variations in melting, dimensional inaccuracy,microhardness, tensile properties, and/or material density. Thesevariations may propagate as sequential layers are added to theworkpieces 116. Additionally, components 204 with such variations mayfail during operation, potentially causing damage to other equipmentincluding catastrophic failures. For example, if a compressor blade orturbine blade fails, the failure may damage other portions of theturbomachine potentially rendering the turbomachine immediatelyinoperable.

However, as shown in FIGS. 3C and 3D, the present disclosure provides abuild plate 118 and/or workpiece-assembly 200 configured to at leastpartially align the top portions of a plurality of workpieces 116 with abuild plane 122. A pretreatment may then be applied to the plurality ofworkpieces 116 to further align the workpiece-interfaces 120 to thebuild plane 122. In an exemplary embodiment, the top portion of aworkpiece 116 provides a workpiece-interface 120, whichworkpiece-interface 120 may be prepared at least in part by performing asubtractive modification to the workpiece 116. Such workpiece-interfaces120 may include a surface, a plane, a tip, or the like generallycorresponding to the highest or tallest portion of the workpiece 116when loaded into the build plate 118. With the top portions aligned bythe workpiece-assembly 200, a plurality of extension segments 206 may beadditively printed on a corresponding plurality of workpieces 116together in a common build using a powder bed fusion process whileassuring that the recoater 134 may apply uniform layers of powder 126across each of the workpieces 116. In some embodiments, the build plate118 may be capable of aligning a plurality of workpieces 116 to a buildplane 122 within a tolerance of 100 microns or less, such as 80 μm orless, such as 60 μm or less, such as 40 μm or less, such as 20 μm orless, or such as 10 μm or less.

The alignment provided by the workpiece-assembly 200 may compensate fordifferences in the size of respective workpieces 116. Such differencesin size may be attributable to workpieces 116 having variations in sizearising from any source, including the workpieces 116 having a differentoriginal configuration, and/or the workpieces 116 having variations insize arising from a subtractive modification performed to prepare aworkpiece-interface 120 on the workpieces 116. In some embodiments, forexample, when the workpieces 116 are airfoils of a turbomachine, such ascompressor blades and/or turbine blades, such airfoils from differentstages of the turbomachine may be secured within a workpiece-assembly200 with the respective workpiece-interfaces 120 (e.g., the top surfacesof the workpieces 116) aligned with one another even though therespective workpieces 116 may have different sizes relative to oneanother.

Now referring to FIG. 4, an exemplary method 400 of additively printingan extension segment 206 on a workpiece-interface 120 of a workpiece 116will be described. The exemplary method may be performed by an additivemanufacturing system 100 as described herein, such as using a controlsystem 106 communicatively coupled to a vision system 102 and anadditive manufacturing machine 104. An exemplary method 400 includes, atstep 402, determining a workpiece-interface 120 from a digitalrepresentation of a field of view 114 having been captured by a visionsystem 102. Determining the workpiece 116 may include determining aworkpiece-interface 120. For example, the exemplary method may includedetermining a workpiece-interface 120 of each of a plurality ofworkpieces 116 from one or more digital representations of one or morefields of view 114 having been captured by a vision system 102.Determining the workpiece-interface 120 may include determining one ormore coordinates of the workpiece-interface 120, for example, ofrespective ones of the plurality of workpieces 116. The one or morefields of view 114 may include one or more workpieces situated inthree-dimensional space, such as a two-dimensional field of view 114 ora three-dimensional field of view 114. For example, the one or morefields of view 114 may include a two-dimensional or three-dimensionaltop view of one or more workpieces 116 individually and/or of aplurality of workpieces 116 collectively, such as a two-dimensional orthree-dimensional top view of the workpiece-interface 120 of one or moreworkpieces 116 individually and/or of a plurality of workpieces 116collectively.

In some embodiments, an exemplary method 400 may include, at step 404,obtaining a digital representation of a field of view 114 using a visionsystem 102, where the field of view 114 includes a workpiece-interface120. This may include obtaining one or more digital representations ofthe one or more fields 114 of view using the vision system 102.Alternatively, an exemplary method 400 may commence with one or moredigital representations already having been obtained from the visionsystem 102.

An exemplary method 400 additionally includes, at step 406, transmittingto an additive manufacturing machine 104, a print command configured toadditively print an extension segment 206 on a workpiece-interface 120,with the print command having been generated based at least in part onthe digital representation of the field of view 114. The print commandmay be configured to additively print the extension segment 206 on aworkpiece-interface 120. One or more print commands may be transmittedto the additive manufacturing machine 104, and the one or more printcommands may be configured to additively print a plurality of extensionsegments 206 with each respective one of the plurality of extensionsegments 206 being located on the workpiece-interface 120 of acorresponding respective one of the plurality of workpieces 116.

The one or more print commands may be generated based at least in parton the one or more digital representations of the one or more fields ofview 114. The exemplary method 400 may optionally include, at step 408,generating a print command based at least in part on a digitalrepresentation of a field of view 114 captured by the vision system 102.This may include generating one or more print commands based at least inpart on one or more digital representations of the one or more fields ofview 114 that include one or more workpieces 116 and/or one or moreworkpiece-interfaces 120 thereof. Alternatively, an exemplary method 400may be performed with one or more print commands already having beengenerated or having been generated separately, such as by the controlsystem 106 or otherwise.

An exemplary method 400 may additionally include, at step 410,additively printing an extension segment 206 on a workpiece-interface120 based at least in part on the print command. This may includeadditively printing respective ones of a plurality of extension segments206 on corresponding respective ones of a plurality of workpieces 120,such as on corresponding respective ones of a plurality ofworkpiece-interfaces 120 thereof. For example, the one or more printcommands may be configured to position respective ones of the pluralityof extension segments 206 on the workpiece-interface 120 ofcorresponding respective ones of the plurality of workpieces 116 basedat least in part on one or more coordinates of the respectiveworkpiece-interface 120.

In some embodiments, the exemplary method 400 may include exposing aworkpiece-interface 120 to a pretreatment, such as using an energy beam144 from the additive manufacturing machine 104. An exemplary method 400may include, at step 412, transmitting to an additive manufacturingmachine 104, a pretreatment command configured to expose theworkpiece-interface 120 to the pretreatment. Step 412 may be performed,for example, after having determined a workpiece-interface 120 at step402. The pretreatment command may be generated based at least in part ona digital representation of a field of view 114 having been captured bythe vision system 102. In some embodiments, the exemplary method 400 mayoptionally include, at step 414, generating the pretreatment commandbased at least in part on the field of view 114.

An exemplary method 400 may additionally include, at step 416, exposinga workpiece-interface 120 to the pretreatment based at least in part onthe pretreatment command. This may include exposing respective ones of aplurality of workpiece-interfaces 120 to respective ones of a pluralityof corresponding pretreatments. For example, the one or morepretreatment commands may be configured to expose respective ones of theplurality of workpiece-interfaces 120 to a corresponding pretreatmentbased at least in part on one or more coordinates of the respectiveworkpiece-interface 120.

After having exposed the workpiece-interface 120 to the pretreatment,the exemplary method 400 may proceed with additively printing anextension segment 206 on the workpiece-interface 120, at step 410.Alternatively, in some embodiments, after having exposed theworkpiece-interface 120 to the pretreatment, the exemplary method 400may return to step 404, to obtain a digital representation of a field ofview 114 using the vision system 102, in which the field of view 114includes a pretreated workpiece-interface 120. In some embodiments, adigital representation that includes a pretreated workpiece-interface120 may more suitable for determining a workpiece-interface at step 402.For example, a pretreated workpiece-interface 120 may allow the visionsystem 102 to more accurately and/or precisely determine theworkpiece-interface 120 at step 402. This, in turn, may allow forgenerating a more accurate and/or precise print command at step 408and/or for more accurately and/or precisely additively printing anextension segment on the workpiece-interface 120 at step 410.

The exemplary method 400 may be performed so as to provide a component204 by additively printing one or more extension segments 206 onto oneor more workpieces 116. In some embodiments, a plurality of workpieces116 may include a plurality of blades for a turbomachine, such ascompressor blades and/or turbine blades, and the corresponding pluralityof extension segments 206 may include a plurality blade tips. Thecomponents 204 may be additively printed in a layer-by-layer mannerusing an additive manufacturing machine 104. For example, the exemplarymethod 400 may include additively printing a first layer of a pluralityof extension segments 206 on the workpiece-interface 120 of respectiveones of the plurality of workpieces 116, followed by additively printinga second layer of the plurality of extension segments 206 on the firstlayer of the plurality of extension segments 206. The first layer may bean interface layer between the workpiece-interface 120 and the extensionsegment 206 to be additively printed thereon. The second layer may be asubsequent layer of the extension segment 206. In some embodiments, acomponent 204 may be additively printed by melting or fusing a singleinterface layer of powered material to the workpiece-interface 120.

Now referring to FIGS. 5A-5C, an exemplary workpiece 116 (FIGS. 5A and5B) and an exemplary component 204 (FIG. 5C) are shown. The exemplaryworkpiece 116 and component 204 may be an airfoil such as a compressorblade or a turbine blade, or any other workpiece 116 or component 204.As shown, the workpiece 116 and component 204 represent a high-pressurecompressor blade (HPC-blade) of a turbomachine. The workpiece 116 may bean originally fabricated workpiece, as well as a workpiece 116 beingrepaired, rebuilt, and so forth.

An exemplary method 400 may include subjecting workpieces 116 to asubtractive modification so as to provide a workpiece-interface 120thereon. This may include cutting, grinding, machining,electrical-discharge machining, brushing, etching, polishing, orotherwise substantively modifying a workpiece 116 so as to provide aworkpiece-interface 120 thereon. The subtractive modification mayinclude removing a subtraction portion 500 (FIG. 5A), so as to provide aworkpiece-interface 120 (FIG. 5B). The subtractive modification mayinclude removing at least a portion of a surface of the workpiece 116that has been worn or damaged. For example, as shown in FIG. 5A, theworkpiece 116 may include artifacts 502, such as microcracks, pits,abrasions, defects, foreign material, depositions, imperfections, andthe like. Such artifacts 502 may commonly appear on the top surface of acompressor or turbine blade as a result of the extreme conditions towhich such blades are subjected. The subtractive modification mayadditionally or alternatively be performed so as to improve bondingbetween the workpiece 116 and the extension segment 206.

When the workpieces 116 include airfoils for a turbomachine, such ascompressor blades and/or turbine blades, as shown in FIGS. 5A and 5B,the subtractive modification may include removing a tip portion of theairfoils, for example, to remove a worn or damaged area. Alternatively,in some embodiments, a component 204 may initially appear as shown inFIG. 5B, without requiring a subtractive modification, or withoutrequiring a substantial portion of the component 204 to be removedduring the subtractive modification. For example, the workpiece 116 maybe an intermediate workpiece 116 in an original fabrication process.

The amount of material removed during the subtractive modification mayvary depending on the nature of the workpiece 116, such as how muchmaterial needs to be subtracted so as to provide a workpiece-interface120 and/or to remove worn or damaged material. The amount of materialremoved may be limited to only a very thin surface layer when thesubtractive modification is intended to prepare a workpiece-interface120 without removing layers of more substantial thickness, or when wearor damage to a workpiece 116 is limited to a thin surface layer.Alternatively, the amount of material removed from a workpiece 116 mayinclude a majority of the workpiece 116, such as when the workpiece 116has larger cracks, breaks, or other damage penetrating deeper into theworkpiece 116.

In some embodiments, the amount of material removed may be from about 1micron to 1 centimeter, such as from about 1 μm to about 1,000 μm, suchas from about 1 μm to about 500 μm, such as from about 1 μm to about 100μm, such as from about 1 μm to about 25 μm, such as from about 100 μm toabout 500 μm, such as from about 500 μm to about 1,000 μm, such as fromabout 100 μm to about 5 mm, such as from about 1 mm to about 5 mm, suchas from about 5 mm to about 1 cm. In still further embodiments, theamount of material removed may be from about 1 centimeter to about 10centimeters, such as from about 1 cm to about 5 cm, such as from about 2cm to about 7 cm, such as from about 5 cm to about 10 cm.

Regardless of the nature of the workpiece 116, as shown in FIG. 5C, anear net shape component 204 may be formed by additively printing anextension segment 206 on the workpiece 116. The near net shape component204 may include an extension segment 206 that is substantially congruentwith the workpiece 116 (and/or the workpiece-interface perimeter 504),such that the extension segment 206 aligns with the workpiece 116(and/or the workpiece-interface perimeter 504) with sufficientcongruency that a near net shape component 204 may be provided withoutrequiring a subsequent subtractive modification apart from surfacefinishing such as polishing, buffing, and the like. The extensionsegments 206 may be additively printed on the respectiveworkpiece-interfaces 120 such that the extension segments 206 aresubstantially congruent with the workpieces 116 and/or theworkpiece-interfaces 120. For example, the workpiece-interface 120 mayhave a workpiece-interface perimeter 504 (FIG. 5B), and the extensionsegments 206 may be additively printed on the respectiveworkpiece-interfaces 120 such that the extension segment 206 issubstantially congruent with the workpiece-interface perimeter 504. Theextension segments 206 may include an interface layer that issubstantially congruent with the workpiece-interface 120, including aninterface layer perimeter that is substantially congruent with theworkpiece-interface perimeter 504. In an exemplary embodiment, anextension segment 206 additively printed on a workpiece-interface 120may be regarded as substantially congruent with the workpiece 116(and/or the workpiece-interface perimeter 504) when the workpiece 116 isan airfoil (e.g., a compressor blade or a turbine blade) having aworkpiece-interface 120 in the form of a crescent shape and theextension segment 206 also has a crescent shape determined at least inpart based on a digital representation of the workpiece-interface 120 ofthe workpiece 116.

In some embodiments, as shown in FIG. 5C, the component 204 may includean overhang 506, such that the extension segment 206 overhangs theworkpiece-interface 120 (e.g., the workpiece-interface perimeter 504).Notwithstanding the presence of the overhang 506, the component 204 maybe regarded as a near net shape component 204, and/or the extensionsegment 206 may be regarded as being substantially congruent with theworkpiece 116 (and/or the workpiece-interface perimeter 504), such aswhen the overhang 506 does not require a subsequent subtractivemodification apart from surface finishing such as polishing, buffing,and the like. The purpose of the overhang 506 may be, for example, toleave a small portion of material available for such surface finishing,including polishing, buffing, and the like. The size of the overhang 506may be selected based on the nature of the finishing processes. Aftersuch finishing processes, the overhang 506 may be substantially removed.

By way of example, in some embodiments, the overhang 506 may be fromabout 1 micron to 1,000 microns, such as from about 1 μm to 500 μm, suchas from about 1 μm to 100 μm, such as from about 1 μm to 50 μm, such asfrom about 1 μm to 25 μm, such as from about 10 μm to 50 μm, such asfrom about 25 μm to 50 μm, such as from about 50 μm to 100 μm, such asfrom about 50 μm to 250 μm, such as from about 250 μm to 500 μm, such asfrom about 500 μm to 1,000 μm, such as about 1.000 μm or less, such asabout 500 μm or less, such as about 250 μm or less, such as about 100 μmor less, such as about, such as about 50 μm or less, or such as about 25μm or less. In an exemplary embodiment, the respective ones of aplurality of extension segments 206 may overhang the correspondingworkpiece-interface 120 of respective ones of the plurality ofworkpieces 116 with the overhang 506 having a maximum overhang distanceof about 1,500 microns or less, such as about 1,000 μm or less, such asabout 500 μm or less, or such as about 100 μm or less or such as about50 μm or less or such as about 25 μm or less. In some embodiments, anextension segment 206 may be regarded as being substantially congruentwith the workpiece 116 and/or the workpiece-interface perimeter 504 whenthe extension segment 206 includes an overhang 506 having a maximumoverhang distance of about 1,500 microns or less, such as about 1,000 μmor less, such as about 500 μm or less, or such as about 100 μm or lessor such as about 50 μm or less or such as about 25 μm or less.

While a workpiece-interface 120 may be relatively small, the additivemanufacturing machine 104 may nevertheless additively print an extensionsegment 206 thereon so as to provide a near net shape component 204. Forexample, as shown in FIG. 5B, a workpiece 116 may have aworkpiece-interface 120 with a cross-sectional width, w, and a height,h_(w), such that a ratio of the height of the workpiece 116 to thecross-sectional width may be from about 1:1 to 1,000:1, such as fromabout 1:1 to 500:1, such as from about 1:1 to 250:1, such as from about1:1 to about 100:1, such as from about 1:1 to about 75:1, such as fromabout 1:1 to about 65:1, such as from about 1:1 to about 35:1, such asfrom about 2:1 to about 100:1, such as from about 5:1 to about 100:1,such as from about 25:1 to about 100:1, such as from about 50:1 to about100:1, such as from 75:1 to about 100:1, such as at least 5:1, such asat least 10:1, such as at least 25:1, such as at least 50:1, such as atleast 75:1 such as at least 100:1, such as at least 250:1, such as atleast 500:1, such as at least 750:1.

As shown in FIG. 5C, an extension segment 206 may have a height, h_(e),such that a ratio of the cross-sectional width, w, of the workpiece 116to the height, h_(e), of the extension segment 206 may be from about1:1,000 to about 1,000:1, such as about 1:1,000 to about 1:500, such asabout 1:500 to about 1:100, such as about 1:100 to about 1:1, such asabout 1:10 to about 1:1, such as about 1:10 to about 10:1, such as about1:1 to about 1:1,000, such as about 1:1 to about 1:10, such as about 1:1to 100:1, such as about 1:1 to about 500:1, or such as about 500:1 toabout 1,000:1.

A ratio of the height, h_(w), of the workpiece 116 to the height, h_(e),of an extension segment 206 to may be from about 2:1 to about 10,000:1,such as from about 10:1 to about 1,000:1, such as from about 100:1 toabout 10,000:1, such as from about 100:1 to about 500:1, such as fromabout 500:1 to about 1,000:1, such as from about 1,000:1 to about10,000:1, such as from about 500:1 to about 5,000:1, such as from about2,500:1 to about 7,500:1, such as at least 2:1, such as at least 100:1,such as at least 500:1, such as at least 1,000:1, such as at least5,000:1, or such as at least 7,000:1.

In some embodiments, a workpiece 116 may have a cross-sectional width offrom about 0.1 millimeters to about 10 centimeters, such as about 0.1 mmto about 5 cm, such as 0.2 mm to about 5 cm, such as about 0.5 mm toabout 5 cm, such as about 0.5 mm to about 1 cm, such as about 0.1 mm toabout 0.5 mm, such as about 0.1 mm to about 5 mm, such as about 0.5 mmto about 10 mm, such as about 0.5 mm to about 5 mm, such as about 0.5 mmto about 3 mm, such as about 1 mm to about 5 mm, such as about 3 mm toabout 10 mm, such as about 1 cm to about 10 cm, such as about 10 cm orless, such as about 5 cm or less, such as about 3 cm or less, such asabout 1 cm or less, such as about 5 mm or less, such as about 3 mm orless, such as about 1 mm or less, such as about 0.5 mm or less. In otherembodiments, a workpiece 116 may have a relatively largercross-sectional width, such as from about 1 cm to about 25 cm, such asfrom about 5 cm to about 15 cm, such as from about 5 cm to about 10 cm,such as at least about 1 cm, such as at least about 5 cm, such as atleast about 10 cm, such as at least about 15 cm, or such as at leastabout 20 cm.

In some embodiments, a workpiece 116 may have a height, h_(w), of fromabout 0.5 centimes to about 25 centimeters, such as about 0.5 cm toabout 5 cm, such as about 0.5 cm to about 3 cm, such as about 1 cm toabout 3 cm, such as about 1 cm to about 10 cm, such as about 10 cm toabout 15 cm, such as about 15 cm to about 25, such as at least about 0.5cm, such as at least 1 cm, such as at least 3 cm, such as at least 5 cm,such as at least 1 about 0 cm, such as at least about 20 cm, such asabout 25 cm or less, such as about 20 cm or less, such as about 15 cm orless, such as about 10 cm or less, such as about 5 cm or less, such asabout 3 cm or less, or such as about 1 cm or less.

In some embodiments, an extension segment 206 may have a height, h_(e),of from about 10 microns to about 20 centimeters, such as about 10 μm toabout 1,000 μm, such as about 20 μm to about 1,000 μm, such as about 50μm to about 500 μm, such as about 100 μm to about 500 μm, such as about100 μm to about 1,000 μm, such as about 100 μm to about 500 μm, such asabout 250 μm to about 750 μm, such as about 500 μm to about 1,000 μm,such as about 1 mm to about 1 cm, such as about 1 mm to about 5 mm, suchas about 1 cm to about 20 cm, such as about 1 cm to about 5 cm, such asabout 5 cm to about 10 cm, such as about 10 cm to about 20 cm, such asabout 20 cm or less, such as about 10 cm or less, such as about 5 cm orless, such as about 1 cm or less, such as about 5 mm or less, such asabout 3 mm or less, such as about 1 mm or less, such as about 500 μm orless, such as about 250 μm or less.

In exemplary embodiment, a workpiece 116 may have a height, h_(w), offrom about 1 cm to 5 cm, and a cross-sectional width, w, of from about0.1 mm to about 5 mm, and an extension segment 206 additively printedthereon may have a height, h_(e), of from about 10 μm to about 5 mm,such as from about 100 μm to about 1 mm, or such as from about 1 mm toabout 5 mm. An exemplary workpiece 116 may have a ratio of the height,h_(w), of the workpiece 116 to the height, h_(e), of an extensionsegment 206 of from about 2:1 to about 10,000:1, such as about 2:1 toabout 10:1, such as about 10:1 to about 50:1, such as about 50:1 toabout 100:1, such as about 100:1 to about 1,000:1, such as about 1,000:1to 5,000:1, such as about 10:1 to about 10,000:1, such as about 2:1 toabout 100:1, such as about 50:1 to about 5,000:1, such as about 100:1 toabout 1,000:1, such as about 1,000:1 to about 5,000:1, such as about1,000:1 to about 10,000:1, such as about 5,000:1 to 1 about 0,000:1,such as at least 2:1, such as at least 10:1, such as at least 50:1, suchas at least 100:1, such as at least 500:1, such as at least 1,000:1,such as at least 5,000:1.

An exemplary workpiece 116 may have a ratio of the cross-sectionalwidth, w, of the workpiece 116 to the height, h_(e), of the extensionsegment 206 of from about 1:50 to about 1,000:1, such as about 1:10 toabout 1:1, such as about 1:5 to about 1:1, such as about 1:1 to about5:1, such as about 5:1 to about 10:1, such as about 10:1 to about 50:1,such as about 50:1 to about 100:1, such as about 100:1 to about 500:1,such as about 500:1 to about 1,000:1, such as about 2:1 to about1,000:1, such as about 1:2 to about 1:1, such as about 1:1 to 1,000:1,such as about 2:1 to about 10:1, such as about 5:1 to about 500:1, suchas about 10:1 to about 100:1, such as about 100:1 to 500:1, such asabout 100:1 to 1.000:1, such as about 500:1 to 1,000:1, such as at least2:1, such as at least 10:1, such as at least 50:1, such as at least100:1, such as at least 500:1.

Referring again to FIGS. 1A and 1B, exemplary methods of obtaining adigital representation of a field of view 114 using a vision system 102will be discussed. When the vision system 102 is integrated with theadditive manufacturing machine 104, the vision system 102 may capturedigital images of the workpieces 116 with the workpieces 116 secured tothe build plate 118, and the build plate 118 secured to the buildplatform 138. The chuck system 140 may position and align the buildplate 118 within the build chamber 128 and on the build platform 138with a high level of precision and accuracy, which also thereby alignsand positions the workpieces 116 within the build chamber 128. Thedigital images may also be captured prior to the build plate 118 havingbeen placed in the build chamber 128 and secured to the build platform138; however, generally it will be preferable to take advantage of thepositioning and alignment provided by the chuck system 140. When thevision system 102 is not integrated with the additive manufacturingmachine 104, digital images may be captured before the build plate 118has been placed in the build chamber 128 and secured to the buildplatform 138, such as in the case of a vision system 102 that isprovided as a separate unit from the additive manufacturing machine 104.

The digital images of the workpieces 116 may be captured during or afterpowder 126 has been added to the build chamber 128. Good contrastbetween the workpiece-interface 120 and the surrounding portions of thearea of interest 600 (and/or between the workpiece-interface perimeter504 and the surrounding portions of the area of interest 600) (e.g.,FIGS. 6A and 6B) may improve the performance of the edge detectionalgorithm. In some embodiments, the digital images may be capturedbefore distributing powder 126 all the way up to the build plane 122and/or across the workpiece-interfaces 120. In some embodiments, imagecapture may be improved by introducing a layer of powder 126 to thebuild chamber 128 that comes to just below the build plane 122 and/orjust below the workpiece-interfaces 120, which is sometimes referred toas a “scratch coating.” For example, the powder 126 may provide animproved background (e.g., better contrast, less reflection, moreuniformity, etc.) that allows the one or more cameras 112 to betterfocus on the workpiece-interfaces 120. Additionally, or in thealternative, in some embodiments a layer of powder 126 may be appliedacross the workpiece-interfaces 120 so as to determine variations inelevation of the respective workpiece-interfaces 120. For example, aregion of a workpiece-interface 120 having a higher elevation mayprotrude from the elevation of a powder 126 layer, while the powderlayer may cover a region of the workpiece-interface 120 having a lowerelevation. Such variations in elevation may be utilized when generatingpretreatment commands. However, powder 126 covering a portion of aworkpiece-interface 120 may obscure the perimeter of theworkpiece-interface 120 and thereby may reduce the quality of thedigital images and/or may affect the reliability of the control system106 in determining the respective workpiece-interfaces 120.

In some embodiments, a layer of powder 126 may be added to the buildchamber 128 that comes to just below the build plane 122 and/or justbelow the workpiece-interfaces 120 prior to the digital images of theworkpieces 116 being captured. The digital images may be captured withsuch a layer of powder 126 in place. Any stray powder 126 may be brushedaway from the workpiece-interfaces 120 prior to capturing the digitalimages. After having captured digital images with such a layer of powder126 just below the build plane 122 and/or just below theworkpiece-interfaces 120, additional powder may be added and additionaldigital images may be captured to determine variations in elevation ofthe respective workpiece-interfaces 120 and/or to generate pretreatmentcommands. In still further embodiments, a skirt (not shown) may beutilized that include slits for the workpiece-interfaces 120 to slipthrough. The skirt may be placed over the workpieces 116 when secured tothe build plate 118, leaving the workpiece-interfaces 120 exposed forpurposes of obtaining digital images, and then the skirt may be removedprior to additive printing.

Exemplary digital representations of one or more fields of view 114captured using the vision system 102 are schematically depicted in FIGS.6A and 6B. FIG. 6A depicts a digital representation of a field of view114 that includes one workpiece 116, and FIG. 6B depicts a digitalrepresentation of one or more fields of view 114 that includes aplurality of workpieces 116. The digital representation depicted in FIG.6B may be captured from a single field of view 114, or a plurality offields of view 114 maybe stitched together to provide a digitalrepresentation of one or more fields of view 114 that includes aplurality of workpieces 116.

As shown in FIGS. 6A and 6B, a field of view 114 may include an area ofinterest 600 corresponding to a workpiece-interface 120 and/or aworkpiece 116 (FIG. 6A) or a plurality of areas of interest 600respectively corresponding to a plurality of workpiece-interfaces 120and/or workpieces 116 (FIG. 6B). Regardless of whether the field of view114 includes one or more areas of interest 600, an area of interest 600may correspond to an expected location of a workpiece-interface 120and/or a workpiece 116 within the field of view 114. The expectedlocation may be determined, for example, based on registration points202 (FIGS. 2A and 2B) mapped to a coordinate system. The control system106 may be configured to process only one or more areas of interest 600within a field of view 114 so as to reduce processing time. As shown,the area of interest 600 includes a digital representation of aworkpiece 116 situated therein. The field of view 114 shown may reflecta top view of the workpiece 116, such that the digital representation ofthe workpiece 116 includes a digital representation of aworkpiece-interface 120, which may include a digital representation ofthe workpiece-interface perimeter 504.

Now referring to FIG. 7A, exemplary methods of determining a workpiece116, a workpiece-interface 120, and/or a workpiece-interface perimeter504 of a workpiece 116 will be discussed. An exemplary method 700includes, at step 702, determining an area of interest 600 within thefield of view 114. The area of interest 600 may correspond to anexpected location of the workpiece 116, the workpiece-interface 120,and/or the workpiece-interface perimeter 504 within the field of view114. An area of interest may be determined based at least in part on amapping of coordinates of the field of view 114 to a registration point202 for a workpiece 116.

An exemplary method 700 may further include, at step 704, determining aworkpiece-interface perimeter 504 within the area of interest 600. Theworkpiece-interface perimeter 504 may be determined using an edgedetection algorithm. An exemplary edge detection algorithm may determinethe workpiece-interface perimeter 504 by determining pixels within thedigital representation of the field of view 114 that havediscontinuities, such as changes in brightness or contrast. Theworkpiece-interface 120 and/or the workpiece 116 may be determined basedon the workpiece-interface perimeter 504 determined using the edgedetection algorithm. Any suitable edge detection algorithm may beutilized, including first or second order operations. Exemplary edgedetection algorithms include a Canny algorithm, a Sobel algorithm, aPrewitt algorithm, a Roberts algorithm, a thresholding algorithm, adifferential algorithm, a fuzzy logic algorithm, and so forth. Thedigital images may also be filtered using edge thinning, a Gaussianfilter, or the like. Exemplary edge detection algorithms may determine aworkpiece-interface perimeter 504 with sub-pixel accuracy.

An exemplary method 700 may include, at step 706, generating a pointcloud 602 corresponding to a workpiece-interface perimeter 504, aworkpiece-interface 120, and/or a workpiece 116. The point cloud mayinclude any desired number of points corresponding to theworkpiece-interface perimeter 504, the workpiece-interface 120, and/orthe workpiece 116. The number of points may be selected based on thedesired level of resolution of the point cloud 602. An exemplary pointcloud 602 is shown in FIGS. 6A and 6B. In some embodiments, as shown inFIG. 6A, a point cloud 602 may be offset by an offset amount 604corresponding to an intended overhang distance between theworkpiece-interface perimeter 504 and an extension segment 206 to beadditively printed thereon. When providing such an offset in the pointcloud 602, the step 706 of generating the point cloud 602 may includedetermining an offset amount 604 and offsetting the series of points ofthe point cloud 602 by the offset amount 604. In some embodiments, theoffset amount may vary as between a first point along the perimeter 504and a second point along the perimeter 504. For example, the offsetamount may be configured to vary according to curvature and/or scan pathof the additive manufacturing tool.

As discussed with reference to FIG. 4, in an exemplary method 400 ofadditively printing an extension segment 206, after determining aworkpiece-interface 120 from the digital representation of the field ofview 114, the exemplary method 400 may include, at step 406,transmitting to an additive manufacturing machine 104, a print commandconfigured to additively print the extension segment 206 on theworkpiece-interface 120, and optionally, the exemplary method 400 mayinclude, at step 408, generating the print command based at least inpart on the field of view 114. In some embodiments, an exemplary method400 may include, at step 412, transmitting to an additive manufacturingmachine 104, a pretreatment command configured to expose theworkpiece-interface 120 to the pretreatment, and optionally, theexemplary method 400 may include, at step 414, generating thepretreatment command based at least in part on the field of view 114. Anexemplary method of generating a print command is described, forexample, with reference to FIG. 7B through FIG. 12. Exemplarypretreatments, exemplary methods of generating a pretreatment command,and exemplary methods of pretreating a workpiece-interface 120, aredescribed, for example, with reference to FIGS. 14-19.

In some embodiments, the print command and/or the pretreatment commandmay be based at least in part on a CAD model, such as an extensionsegment-CAD model that includes a model of one or more extensionsegments 206 configured to be additively printed on one or moreworkpieces 116, such as on the respective workpiece-interfaces 120. Theexemplary method 400 may include determining an extension segment-CADmodel and/or generating an extension segment-CAD model. Additionally, orin the alternative, the step 408 of generating a print command based atleast in part on the field of view 114 captured by the vision system 102may include determining an extension segment-CAD model and/or generatingan extension segment-CAD model. Further additionally, or in thealternative, the step 414 of generating a pretreatment command based atleast in part on the field of view 114 captured by the vision system 102may include determining an extension segment-CAD model and/or generatingan extension segment-CAD model.

Now referring to FIG. 7B, an exemplary method 750 of generating a printcommand will be described. The exemplary method 750 may be performed,for example, in connection with step 408 in the exemplary method 400 ofadditively printing an extension segment 206 shown in FIG. 4. Anexemplary method 750 may include, at step 752, determining and/orgenerating an extension segment-CAD model; at step 754, slicing theextension segment-CAD model; and at step 756, determining a scan pathand an additive printing area for each slice of the extensionsegment-CAD model. After determining a scan path and an additiveprinting area for a slice of the extension segment-CAD model, at step756, the exemplary method 750 may proceed with determining, at step 758,whether there is another slice, and if so, the exemplary method 750 mayproceed to step 756, providing for determining a scan path and anadditive printing area for a next slice of the extension segment-CADmodel 800 (e.g., FIG. 8A). The exemplary method 750 may end, at step760, when there are no additional slices for which a scan path andadditive printing area may be determined. The number of slices maydepend on the size (e.g., height, thickness) of the extension segment(s)in the extension segment-CAD model, as well as the desired thickness ofthe layers of powder 126 or other material that may be used toadditively print the extension segment(s).

FIG. 8A shows an exemplary extension segment-CAD model 800. Theexemplary extension segment-CAD model 800 may include a model of one ormore extension segments 206. As shown, the extension segment-CAD model800 includes a plurality of models of extension segments 802. The modelsof the extension segments 802 respectively conform to the location andshape of a plurality of corresponding workpieces 116 upon which theplurality of extension segments 206 are to be respectively additivelyprinted. For example, the respective models of an extension segment 802may be aligned with coordinates that respectively correspond to theregistration points 202 of a plurality of workpieces 116 secured to abuild plate 118, and/or the models of the extension segments 802 mayinclude a model-interface 804 that is substantially congruent with theworkpiece-interface 120 of the corresponding workpiece 116. Themodel-interface 804 may be defined by a model-interface perimeter 806,and the model-interface perimeter 806 may be substantially congruentwith the workpiece-interface perimeter 504 of the respective workpiece116. A model of the extension segment 802 may include a height, h_(e),extending from a model-interface 804 to a top surface 808.

In some embodiments, a plurality of workpieces 116 onto which extensionsegments 206 are to be printed may differ from one another, and yet theextension segment-CAD model 800 may nevertheless include a model of theplurality of extension segments 802 conforming to the location and shapeof respective ones of the plurality of workpieces 116. The model mayinclude one or more model-interfaces 804 that are substantiallycongruent with corresponding workpiece-interfaces 120 and/or one or moremodel-interface perimeter 806 that are substantially congruent withcorresponding workpiece-interface perimeters 504. An extensionsegment-CAD model 800 may be determined and/or generated based at leastin part on a CAD model, such as a library-CAD model selected from adatabase or CAD model library. The database or CAD model library mayinclude a plurality of library-CAD models from which an extensionsegment-CAD model 800 may be determined and/or generated.

An exemplary library-CAD model is shown in FIG. 8B. A library-CAD model850 may include a nominal model of one or more nominal workpieces 116,components 204, or extension segments 206. For example, as shown in FIG.8B, the library-CAD model 850 may include a nominal model 852 of one ormore components 204 intended to be repaired, rebuilt, and/or upgraded.As shown, the library-CAD model 850 may include a nominal model 852 of aplurality of nominal components 204. The library-CAD model 850 mayalternatively include a single nominal component 204. Additionally, orin the alternative, the library-CAD model 850 may include one or morenominal models 852 of a nominal extension segment 206, and/or one ormore nominal models 852 of a nominal workpiece 116. In some embodiments,the CAD model library may include one or more extension segment-CADmodels 800, which may include one or more previously determined and/orpreviously generated extension segment-CAD models 800 from whichsubsequent extension segment-CAD models 800 may be determined and/orgenerated.

As shown in FIG. 8B, a nominal model-interface 854 may be determinedfrom a nominal model 852. A nominal model-interface 854 may correspondto an expected location of a workpiece-interface 120 of a nominalworkpiece 116 associated with the library-CAD model 850. The nominalmodel-interface 854 may be defined by a nominal model-interfaceperimeter 856, and the nominal model-interface perimeter 856 may or maynot be substantially congruent with the workpiece-interface perimeter504 of the respective workpiece 116. The nominal model-interface 854 maybe located at any z-directional position of the nominal model, includingup to a nominal top surface 858 of the nominal model 852.

In some embodiments, a library-CAD model 850 or an extension segment-CADmodel 800 may be an actual CAD model from which one or more components204 were originally fabricated, or the library-CAD model may be a copyor a modified version of a CAD model from which one or more components204 were originally fabricated. While a library-CAD model 850 maygenerally correspond to one or more workpieces 116 onto which anextension segment 206 is to be additively printed, the one or moreworkpieces 116 may differ from their original net shape in varyingdegrees from one workpiece 116 to the next. A difference from suchoriginal net shape may exits, for example, when a workpiece 116 has beendeformed or damaged such as from exposure to extreme temperatureoperating conditions and/or from rubbing or impacts from foreignobjects. A difference in original net shape may also exist because ofvariations in a subtractive modification performed to prepare aworkpiece-interface 120 on the workpieces 116. However, the presentdisclosure provides for generating extension-segment CAD models 800 thatinclude a plurality of models of extension segments 802 respectivelyconforming to the location and shape of a plurality of workpieces 116upon which the plurality of extension segments 206 are to berespectively additively printed based on an extension-segment CAD model800 and/or the models of the extension segments 802 therein.

An exemplary method of generating an extension segment-CAD model 800 isshown in FIGS. 9A and 9B. As shown in FIG. 9A, an exemplary method 900of generating an extension segment-CAD model 800 may be performed foreach of a plurality of workpieces 116. An exemplary method 900 mayinclude, at step 902, determining in a library-CAD model, a nominalmodel-interface 854 traversing a nominal model corresponding to arespective one of the plurality of workpieces 116. The nominal model mayinclude a model of a nominal component 204, such as a model of acomponent 204 from which the workpieces 116 may have originated. Theworkpieces 116 may, however, differ from a component 204 having beenadditively manufactured according to the nominal model, for example,because of damage or wear incurred by the workpieces 116 as a result ofthe environment with which the component 204 was used, and/or from asubtractive modification performed to prepare the workpiece 116 for anextension segment 206 to be additively printed thereon. The nominalmodel may additionally or alternatively include a model of a nominalworkpiece, such as a nominal model of a workpiece 116 produced bysubjecting a nominal component 204 to a subtractive modification processto provide a workpiece-interface 120. The nominal model may additionallyor alternatively include a model of a nominal extension segment 802,such as a nominal model of an extension segment 802 corresponding to anominal workpiece 116.

Determining a nominal model-interface 854 may include determining aplane traversing the library-CAD model at a determined height. Thedetermined height may correspond to a height of an expected location ofa workpiece-interface 120 for a nominal workpiece 116. By way ofexample, a library-CAD model may include a model of a nominal component204 corresponding to the workpiece, and the workpiece 116 may have beensubjected to a subtractive modification, such as to provide aworkpiece-interface 120. An expected location of a workpiece-interface120 may be determined based at least in part on the nature of thesubtractive modification, such as based on an expected amount ofmaterial removed or a resulting change in height of the workpiece 116 asa result of the subtractive modification.

Additionally, or in the alternative, the determined height maycorrespond to a height of a workpiece-interface 120 as determined from adigital representation of the workpiece 116. The height of aworkpiece-interface 120 may be measured based at least in part on one ormore dimensions of the workpiece 116 obtained from the digitalrepresentation of the workpiece, and a nominal model-interface 854 maybe determined based at least in part on the measured height.Additionally, or in the alternative, the height of theworkpiece-interface 120 may be measured based at least in part one ormore dimensions of a workpiece alignment system 200 captured in a fieldof view 114. For example, a height of the workpiece-interface 120 may bedetermined based at least in part on the height of a workpiece shoe 214,or based at least in part on a difference between the height of theworkpiece-interface 120 and the height of a workpiece shoe 214, or basedat least in part on a difference between the height of theworkpiece-interface 120 and the height of the build plate 118.

In some embodiments, a nominal model-interface 854 may be determinedusing a best-fit algorithm. Determining the nominal model-interface 854traversing the library-CAD model 850 may include determining a planetraversing the library-CAD model that meets a metric associated with abest-fit algorithm applied with respect to the digital representation ofthe workpiece-interface 120. The best-fit algorithm may compare one ormore planes traversing the library-CAD model to the digitalrepresentation of the workpiece-interface 120 until a compared planesatisfies the best-fit metric. The nominal model-interface 854 may bedetermined based at least in part on a plane that satisfies the best-fitmetric. For example, a plane that satisfies the best-fit metric may bedetermined to be the nominal model-interface 854.

Still referring to FIG. 9A, an exemplary method 900 of determiningand/or generating an extension segment-CAD model 800 may include, atstep 904, comparing the nominal model-interface 854 of the library-CADmodel to a digital representation of the workpiece-interface 120 of therespective ones of the plurality of workpieces 116. The digitalrepresentation may have been previously or concurrently obtained using avision system 102 that has a field of view 114 including theworkpiece-interface 120 of the respective one of the plurality ofworkpieces 116. The comparison may be performed using an image matchingalgorithm. In some embodiments, comparing the nominal model-interface854 to the digital representation of the workpiece-interface 120 mayinclude, at step 906, determining whether the nominal model-interface854 and the digital representation of the workpiece-interface 120sufficiently match one another. However, in some embodiments a matchingstep 906 need not be included.

When included, a matching step 906 may include comparing one or morecoordinates of the nominal model-interface 854 with one or morecoordinates of the digital representation of the workpiece-interface 120and determining one or more differences therebetween. The comparing step904 may additionally or alternatively include comparing one or morecoordinates of the one or more registration points 202 with acorresponding one or more coordinates of the nominal model-interface 854of the library-CAD model and determining one or more differencestherebetween. The registration points 202 may correspond to locations ofrespective ones of a plurality of workpieces 116 onto which respectiveones of a plurality of extension segments 206 are to be additivelyprinted using the additive manufacturing machine 104. The comparing step904 and the matching step 906 may be performed separately or together aspart of the same step. In some embodiments, the matching step 906 maydetermine whether there is a partial match, a close match, or no matchbetween the nominal model-interface 854 and the workpiece-interface 120.Alternatively, the matching step 906 may determine whether there is anymatch (e.g., at least a partial match), or no match between the nominalmodel-interface 854 and the workpiece-interface 120.

When the matching step 906 determines that there is at least a partialmatch between the nominal model-interface 854 and theworkpiece-interface 120, the exemplary method 900 may proceed to step908, providing for generating a model of an extension segment 802 basedat least in part on the nominal model-interface 854. Step 908 provides amodel of an extension segment 802 conforming to the digitalrepresentation of the workpiece-interface 120 of the respective one ofthe plurality of workpieces 116 such that the model of the extensionsegment 802 is configured to be additively printed on theworkpiece-interface 120 of the respective one of the plurality ofworkpieces 116.

When the matching step 906 determines that there is not at least apartial match between the nominal model-interface 854 and theworkpiece-interface 120, the exemplary method 900 may return to step 902so as to determine a different nominal model-interface 854 and tocompare the different nominal model-interface 854 to the digitalrepresentation of the workpiece-interface 120. The different nominalmodel-interface 854 may be selected form the same library-CAD model or adifferent library-CAD model.

In some embodiments, the matching step 906 may include determiningwhether there is more than a partial match, such as a close matchbetween the nominal model-interface 854 and the workpiece-interface 120.When the matching step 906 determines that there is a close matchbetween the nominal model-interface 854 and the workpiece-interface 120,the exemplary method 900 may include, at step 910, selecting the nominalmodel-interface 854 and/or at least a three-dimensional portion of thenominal model from the library-CAD model based at least in part on thecomparison. For example, the comparison may determine that the selectednominal model-interface 854 and/or the nominal model from thelibrary-CAD model conforms to the digital representation of theworkpiece-interface 120 of the respective one of the plurality ofworkpieces 116, such that the selected nominal model-interface 854 maybe aligned with coordinates that correspond to the digitalrepresentation of the workpiece-interface 120, and/or the selectednominal model-interface 854 may be substantially congruent with thedigital representation of the workpiece-interface 120. In variousexemplary embodiments, step 910 may include selecting the nominal modelfor a respective workpiece, selecting a three-dimensional portion of thenominal model for a respective workpiece 116 (which may include thenominal model-interface 854), and/or selecting only the nominalmodel-interface 854 for the respective workpiece 116.

When a nominal model or a three-dimensional portion thereof is selectedat step 908, the exemplary method 900 may include determining anextension-segment-CAD model from the library-CAD model. For example, alibrary-CAD model that includes a nominal extension segment 206 may bedetermined to sufficiently match a workpiece-interface 120 such that anextension segment 206 may be additively printed on theworkpiece-interface 120 without requiring transforming or extending thenominal model-interface 854 at steps 910, 912. On the other hand, whenthe library-CAD model includes a model of a nominal component 204 or amodel of a nominal workpiece 116, rather than a model of a nominalextension segment 206, the exemplary method 900 may proceed withgenerating a model of an extension segment 802 at step 908, for example,so as to provide a model of an extension segment 802 rather than a modelof a component 204 or workpiece 116. The model of the extension segment802 generated at step 908 may be configured to be additively printed onthe workpiece-interface 120 of the respective one of the plurality ofworkpieces 116, whereas a model of a component 204 or workpiece 116would not be so configured even if the nominal model-interface 854closely matched the workpiece-interface 120.

In exemplary methods 900 that do not include a matching step 906, anexemplary method may proceed to generating a model of an extensionsegment 802 based at least in part on the nominal model-interface 854 atstep 908 after having compared the nominal model-interface 854 to thedigital representation of the workpiece-interface 120 at step 904. Insome embodiments, steps 904 and 908 may be combined into a single step,such that comparing the nominal model-interface 854 to the digitalrepresentation of the workpiece-interface 120 may be part of the processof generating a model of an extension segment 802 based at least in parton the nominal model-interface 854.

After having generated and/or selected a model of an extension segment802 at steps 908, 910, an exemplary method 900 may ascertain, at step912, whether the plurality of workpieces 116 includes another workpiece116. When there is another workpiece, the exemplary method 900 mayinclude repeating the determining step 902 and subsequent steps throughto step 912. When step 912 indicates that there are no additionalworkpieces 116, the exemplary method 900 may proceed with step 914,which provides for outputting a model of a plurality of extensionsegments 802 respectively configured to be additively printed on thecorresponding workpiece-interface 120 of the respective ones of theplurality of workpieces 116. The model may be an extension segment-CADmodel 800, and the model may be based at least in part on the selectingand/or transforming of the nominal model-interface 854 and/or thenominal model from the library-CAD model.

The model of the plurality of extension segments 802 may be output atstep 914 concurrently as, or subsequently after, each additionalworkpiece 116 is generated and/or selected at steps 908, 910. In someembodiments, outputting the model may include stitching together aplurality of models, such as models having been respectively selectedand/or transformed and generated for respective ones of the plurality ofworkpieces 116. While an exemplary method 900 of determining and/orgenerating an extension segment-CAD model 800 has been described withrespect to a plurality of extension segments 206, it will be appreciatedthat an extension segment-CAD model 800 may also be determined and/orgenerated for a single extension segment 206. For example, the exemplarymethod 900 may be performed for a single extension segment 206.

Referring now to FIG. 9B, one or more steps will be described that maybe included in the step 908 of generating a model of an extensionsegment 802 (FIG. 9A). The steps shown in FIG. 9B may be includedindividually or together with one or more other steps. When generating amodel of an extension segment 802, one or more steps shown in FIG. 9Bmay be performed, and the particular steps performed may depend at leastin part on whether the nominal model-interface 854 provides a partialmatch or a close match at step 906 (FIG. 9A), and/or whether the nominalmodel-interface 854 or at least a three-dimensional portion of thenominal model are selected at step 910 (FIG. 9A).

As shown in FIG. 9B, generating a model of an extension segment 802 atstep 908 may include an extracting step 916, such that an extensionsegment 206 may be generated based at least in part on a nominalmodel-interface 854 and/or a three-dimensional portion of a nominalmodel corresponding to the nominal model-interface 854. Alternatively,the extracting step 916 may be omitted, for example, such that a nominalmodel may itself be configured to be additively printed on aworkpiece-interface 120. The step 908 of generating a model of anextension segment 802 may additionally or alternatively include atransforming step 918, such that a nominal model-interface 854 may beconformed to the digital representation of the workpiece-interface 120.Alternatively, the transforming step 918 may be omitted, for example,when a nominal model-interface 854 already conforms to the digitalrepresentation of the workpiece-interface 120. The step 908 ofgenerating a model of an extension segment 802 may further additionallyor alternatively include an extending step 920, such that a nominalmodel-interface 854 or a transformed model-interface 804 may be extendedso as to provide a three-dimensional model of an extension segment 802.Alternatively, the extending step 920 may be omitted, for example, whengenerating a model of an extension segment 802 from a three-dimensionalportion of the nominal model.

In some embodiments, at step 916, generating a model of an extensionsegment 802 may optionally include extracting from a nominal model basedat least in part on the comparison at step 904, 906, a nominalmodel-interface 854 and/or a three-dimensional portion of the nominalmodel corresponding to the nominal model-interface 854. The extractingstep may be performed following the comparing step 904, following thematching step 906, or following the selecting step 910.

In some embodiments, generating a model of an extension segment 802 mayoptionally include, at step 918, transforming a nominal model-interface854 based at least in part on the comparison at step 904, 906, so as toprovide a transformed model-interface 804 conforming to the digitalrepresentation of the workpiece-interface 120 of the respective one ofthe plurality of workpieces 116. The transforming step may include onemore transforming operations, including aligning, altering, modifying,contorting, distorting, deforming, correcting, adjusting, revising,straightening, tilting, rotating, bending, twisting, or editing, as wellas combinations of these. The particular transforming operation(s) maybe selected based at least in part on the comparison such that thetransforming operation(s) conforms the nominal model-interface 854 tothe digital representation of the workpiece-interface 120.

The transforming step 918 may be performed following the comparing step904 and/or following the matching step 906. Additionally, or in thealternative, the transforming step 918 may be performed following theextracting step 916. An exemplary method 900 may include extracting thenominal model-interface 854 from the nominal model and then proceedingto step 918, providing for transforming the nominal model-interface 854based at least in part on the comparison at step 904, 906, so as toprovide a transformed model-interface 804 conforming to the digitalrepresentation of the workpiece-interface 120 of the respective one ofthe plurality of workpieces 116.

In some embodiments, generating a model of an extension segment 802 mayoptionally include, at step 920, extending the transformedmodel-interface 804, such that the extension segment 206 is configuredto be additively printed on the workpiece-interface 120 of therespective one of the plurality of workpieces 116. Step 920 may beperformed after having transformed the nominal model-interface 854 atstep 918. Alternatively, in some embodiments, the extending step 920 maybe combined with the transforming step 918.

Further additionally, or in the alternative, step 918 may follow step910 (FIG. 9A), providing for extending a nominal model-interface 854that has been selected at step 910. For example, when a nominalmodel-interface 854 closely matches a digital representation of aworkpiece-interface 120, such as may be determined at step 906, thetransforming step 918 may be omitted from the step of generating a modelof an extension segment 802 at step 908. Regardless of whether thenominal model-interface 854 is transformed at step 918 or selected atstep 910 with the transforming step 918 being omitted, the extensionsegment 206 resulting from the extending step 912 may be configured tobe additively printed on the workpiece-interface 120 of the respectiveone of the plurality of workpieces 116.

In an exemplary embodiment, generating a model of an extension segment802 at step 908 may include, at step 916, extracting from the nominalmodel based at least in part on the comparison of the nominalmodel-interface 854 to a digital representation of workpiece-interface120; at step 918, transforming the nominal model-interface 854 based atleast in part on the comparison so as to provide a transformedmodel-interface 804 conforming to the digital representation of theworkpiece-interface 120; and at step 920, extending the transformedmodel-interface 804 so as to provide an extension segment 206 configuredto be additively printed on the workpiece-interface 120.

Referring still to FIG. 9B, in another embodiment, the step 908 ofgenerating a model of a nominal extension segment 206 may include, atstep 916, extracting from the nominal model a three-dimensional portionof the nominal model. The three-dimensional portion may correspond tothe nominal model-interface 854. For example, the three-dimensionalportion may include the portion of the nominal model above the nominalmodel-interface 854 and may include the nominal model-interface 854. Theportion of the nominal model below the three-dimensional interface maybe deleted from the nominal model and/or may remain unextracted. Thethree-dimensional portion may have a height corresponding to the heightof an extension segment 206 being generated at step 908.

In some embodiments, generating a model of an extension segment 802 mayoptionally include, at step 922, transforming a three-dimensionalportion of a nominal model corresponding to a nominal model-interface854 based at least in part on the comparison at step 904, 906, so as toprovide a model of an extension segment 802 conforming to the digitalrepresentation of the workpiece-interface 120 of the respective one ofthe plurality of workpieces 116. The model of the extension segment 802so provided may be configured to be additively printed on theworkpiece-interface 120 of the respective one of the plurality ofworkpieces 116. The three-dimensional portion of the nominal modeltransformed at step 922 may include a three-dimensional portionextracted at step 916 or at least a three-dimensional portion of anominal model selected at step 910 (FIG. 9A). In some embodiments, theat least a three-dimensional portion of a nominal model selected at step910 may include the nominal model as a whole, such as when the nominalmodel is a model of a nominal extension segment 206.

The step 922 of transforming a three-dimensional portion may includetransforming the nominal model-interface 854 of the three-dimensionalportion, and may include one more transforming operations, includingaligning, altering, modifying, contorting, distorting, deforming,correcting, adjusting, revising, straightening, tilting, rotating,bending, twisting, or editing, as well as combinations of these. Theparticular transforming operation(s) at step 922 may be selected basedat least in part on the comparison such that the transformingoperation(s) conforms the nominal model-interface 854 to the digitalrepresentation of the workpiece-interface 120. Additionally, or in thealternative, the step 922 of transforming a three-dimensional portionmay include extending the nominal model-interface 854 so as to providean extension segment 206 conforming to the digital representation of theworkpiece-interface of the respective one of the plurality of workpieces116.

Now referring to FIGS. 10A-10D, exemplary transforming operations 1000will be described, which may be performed at step 910 in the exemplarymethod 900 of generating an extension segment-CAD model 800. Any one ormore transforming operations 1000 may be performed so as to conform anominal model-interface 854 to a digital representation of aworkpiece-interface 120. Such transforming operations 1000 may beperformed when transforming the nominal model-interface 854, forexample, as part of a transforming step 910 in an exemplary method 400of additively printing an extension segment 206 and/or in an exemplarymethod 900 of determining and/or generating an extension segment-CADmodel 800.

The nominal model-interface 854 may differ from a digital representationof a workpiece-interface 120, for example, because of a change to theshape of a workpiece 116 while in service, or any other differencebetween workpiece-interface 120 and the library-CAD model from which thenominal model-interface 854 was selected. Additionally, or in thealternative, a nominal model-interface 854 may be selected at a heightthat differs from the height of the workpiece-interface 120 even thoughthe nominal model corresponds to the component 204. Such a difference inheight may result in a corresponding difference between the nominalmodel-interface 854 and the workpiece-interface 120. The transformingoperation 1000 may be performed so as to compensate for a differencebetween the nominal model-interface 854 and the workpiece-interface 120,regardless of the underlying source for such difference.

FIG. 10A shows an exemplary transforming operation 1000 that includesshifting at least a portion of a nominal model-interface 854 so as toconform the nominal model-interface 854 with a digital representation ofa workpiece-interface 120. As shown in FIG. 10A, the nominalmodel-interface 854 is shifted to the right. However, it will beappreciated that a transforming operation 1000 may include shifting anominal model-interface 854 in any direction, including any directionalong a 360-degree axis.

FIG. 10B shows an exemplary transforming operation 1000 that includesrotating at least a portion of a nominal model-interface 854 so as toconform the nominal model-interface 854 with a digital representation ofa workpiece-interface 120. As shown in FIG. 10B, the nominalmodel-interface 854 is rotated counterclockwise. However, it will beappreciated that a transforming operation 1000 may include rotating anominal model-interface 854 in any direction.

FIG. 10C shows an exemplary transforming operation 1000 that includesbending at least a portion of a nominal model-interface 854 so as toconform the nominal model-interface 854 to a digital representation of aworkpiece-interface 120. As shown in FIG. 10C, by way of example nominalmodel-interface 854 generally aligns with the workpiece-interface 120 ata middle region, while outward regions are subjected to a bendingtransforming operation. However, it will be appreciated that atransforming operation 1000 may include bending a portion of a nominalmodel-interface 854 in any direction.

FIG. 10D shows an exemplary transforming operation 1000 that includesscaling at least a portion of a nominal model-interface 854 so as toconform the nominal model-interface 854 with a digital representation ofa workpiece-interface 120. As shown in FIG. 10D, by way of example, thenominal model-interface 854 is scaled downward so as to conform to theworkpiece-interface 120. However, it will be appreciated that atransforming operation 1000 may additionally or alternatively includescaling a nominal model-interface 854 upward.

Any one or more transforming operations may be carried out alone or incombination with one another, and as to all or a portion of a nominalmodel-interface 854. In some embodiments, transforming a nominalmodel-interface 854, such as at step 910 of the exemplary method 900,may include aligning at least a portion of the nominal model-interface854 with a digital representation of a workpiece-interface 120. Suchaligning may include aligning one or more coordinates of the nominalmodel-interface 854 with one or more coordinates of the digitalrepresentation of the workpiece-interface 120. By way of example, suchaligning may be performed, at least in part, using a shifting, rotating,bending, and/or scaling transforming operation as described withreference to FIGS. 10A-11D. Additionally, or in the alternative,transforming the nominal model-interface 854 may include a firsttransforming operation selected to align at least a first portion of thenominal model-interface 854 with a digital representation of aworkpiece-interface 120, such as using a shifting and/or rotatingtransforming operation as described with reference to FIGS. 10A and 10B,followed by a second transforming operation selected to align at least asecond portion of the nominal model-interface 854 with the digitalrepresentation of the workpiece-interface 120 such as using a bendingand/or scaling transforming operation as described with reference toFIGS. 10C and 10D.

The first transforming operation may be selected to align a first one ormore coordinates of the nominal model-interface 854 with a first one ormore coordinates of the digital representation of theworkpiece-interface 120, and the second transforming operation may beselected to align a second one or more coordinates of the nominalmodel-interface 854 with a second one or more coordinates of the digitalrepresentation of the workpiece-interface 120.

The first one or more coordinates of the nominal model-interface 854 mayinclude coordinates for a center point of the nominal model-interface854 and/or one or more coordinates along the nominal model-interfaceperimeter 856 of the nominal model-interface 854, such as a maximum orminimum X coordinate or a maximum or minimum Y coordinate along thenominal model-interface perimeter 856. The first one or more coordinatesof the workpiece-interface 120 may include coordinates for a centerpoint of the workpiece-interface 120 and/or one or more coordinatesalong the workpiece-interface perimeter 504 of the workpiece-interface120, such as a maximum or minimum X coordinate or a maximum or minimum Ycoordinate of the workpiece-interface perimeter 504. The firsttransforming operation may be configured to align the center point ofthe nominal model-interface 854 with the center point of theworkpiece-interface 120, and/or to align a maximum or minimum Xcoordinate or a maximum or minimum Y coordinate along the nominalmodel-interface perimeter 856 with a corresponding maximum or minimum Xor Y coordinate along the workpiece-interface perimeter 504.

The second one or more coordinates of the nominal model-interface 854may include one or more coordinates along the nominal model-interfaceperimeter 856 of the nominal model-interface 854, and the second one ormore coordinates of the workpiece-interface 120 may include one or morecoordinates along the workpiece-interface perimeter 504. The second oneor more coordinates of the nominal model-interface 854 and/or the secondone or more coordinates of the workpiece-interface 120 may be selectedbased on a comparison of the workpiece-interface 120. Such comparisonmay be performed, for example, after the first transforming operation.

Coordinates may be selected for the second transforming operation basedon a difference between coordinates for a point along the nominalmodel-interface perimeter 856 as compared to coordinates of acorresponding point along the workpiece-interface perimeter 504. Forexample, coordinates for such a point may be selected when thecoordinates differ by a threshold amount. The threshold amount may beselected based at least in part on a degree of conformance sufficient toprovide a near net shape component 204 when additively printing anextension segment 206 conformed to the workpiece-interface 120 based atleast in part on the one or more transforming operations. In this way,once the nominal model-interface 854 has been aligned with theworkpiece-interface 120 according to the first transforming operation,one or more second transforming operations may be performed asdetermined by such comparison relative to such threshold amount.

The one or more second transforming operations may be performed to theextent needed to sufficiently conform the nominal model-interface 854 tothe workpiece-interface 120 so as to obtain a near net shape component204. In some embodiments, a difference may exist between coordinates ofone or more points along the nominal model-interface perimeter 856relative to coordinates of corresponding points along theworkpiece-interface perimeter 504, while still sufficiently conformingthe nominal model-interface 854 to the workpiece-interface 120 so as toprovide a near net shape component 204. For example, such difference maybe an amount that is at least less than an overhang distance for anoverhang 506.

In some embodiments, a transforming operation may provide for anoverhang 506 between the workpiece-interface 120 and the model-interface804, such that the model-interface 804 overhangs the workpiece-interface120 by an overhang distance. For example, a transforming operation mayinclude determining an offset amount 604 and transforming at least aportion of a nominal model-interface 854 by the offset amount 604. Theoffset amount 604 may correspond to an overhang distance for at least aportion of the extension segment 206.

Now referring to FIGS. 11A and 11B, and FIGS. 12A-12D, exemplary methodsof extending a model-interface 804 will be described. FIG. 11A shows anominal model, such as from a library-CAD model 850. FIG. 11B shows amodel of an extension segment 802, such as in an extension segment-CADmodel 800, generated based at least in part on the nominalmodel-interface 854, such as in steps including extending the nominalmodel-interface 854. FIG. 12 shows a flow chart depicting exemplarymethods of extending a model-interface 804 so as to provide a model ofthe extension segment 802 configured to be additively printed on aworkpiece-interface 120 of a respective workpiece 116.

Exemplary methods of extending a model-interface 804 may be performedstarting from a nominal or transformed model-interface 804 and/or athree-dimensional portion of a nominal model. As described withreference to FIGS. 9A and 9B, exemplary methods 900 of generating anextension segment-CAD model 800 may include, at step 920, extending aselected nominal model-interface 854 or a transformed model-interface804. Additionally, the step 922 of transforming a three-dimensionalportion may include extending the nominal model-interface 854. Such anominal model-interface 854 may have been extracted from the nominalmodel or may remain part of the nominal model when extending the nominalmodel-interface 854. When a nominal model-interface 854 and/or athree-dimensional portion of a nominal model remains part of the nominalmodel when extending, the resulting extension segment 206 may beextracted from the nominal model, for example, by extracting athree-dimensional portion of a nominal model corresponding to thenominal model-interface 854 as described with reference to step 916.

As shown in FIG. 11B, a model of an extension segment 802 may include aheight, h_(e), extending from a model-interface 804 to a top surface808. The height, h_(e), for an extension segment 802 may be determinedfrom a nominal model 852. For example, the height of an extensionsegment 206, h_(e), may correspond to the z-directional distance from anominal model-interface 854 to a nominal top surface 858 of the nominalmodel 852. Alternatively, the height of an extension segment 206, h_(e),may be specified independently from the nominal model 852. An exemplarymodel of an extension segment 802 may be extended from themodel-interface 804 to the nominal top surface 858 of the nominal model852.

In some embodiments, a model of an extension segment 802 may include aregion extending from the model-interface 804 to the top surface 808 ofthe model. Additionally, or in the alternative, as shown in FIG. 11B, amodel of an extension segment 802 may include a plurality of extensionsegment slices 1100 between the model-interface 804 to the top surface808 of the model. The extension segment slices 1100 may correspond tonominal model slices 1102 in the nominal model 852. The nominal modelslices 1102 and/or the extension segment slices 1100 may have anydesired z-directional spacing. The nominal model slices 1102 may includea nominal model-interface 854 and/or one or more nominal extended-planes1104. The nominal model slices 1102 may correspond to the z-directionalresolution of the nominal model, and the extension segment slices 1100may correspond to the z-directional resolution of the model of theextension segment 802. In some embodiments, the z-directional resolutionof the model of the extension segment 802 may differ from thez-directional resolution of the nominal model 852. For example, thez-directional resolution of the model of the extension segment 802 maybe increased or decreased relative to the z-directional resolution ofthe nominal model 852.

As shown in FIG. 12A, an exemplary method 1200 of extending amodel-interface 804 may include, at step 1202, determining a height of aworkpiece 116 based at least in part on a digital representation of afield of view 114 that includes at least a portion of the workpiece, atstep 1204, determining a height for an extension segment 206 to beadditively printed on a workpiece-interface 120 of the workpiece 116,and at step 1206, extending the model-interface 804 in the z-directionby an amount corresponding to the height for the extension segment 206.The model-interface 804 may be extended in the z-direction within anominal model and then a resulting model of an extension segment 802 maybe extracted therefrom. Alternatively, the model-interface 804 may beextracted from the nominal model, and then the model-interface 804 maybe extended in the z-direction by an amount corresponding to the heightfor the extension segment 206 within a model of the extension segment802 being generated.

Exemplary methods of extending a model-interface 804 at step 1206 areshown in FIGS. 12B-12D. As shown in FIG. 12B, extending amodel-interface 804 in the z-direction may include, at step 1208,positioning the model-interface 804 at an elevation corresponding to abuild plane 122 of an additive manufacturing machine 104; at step 1210,positioning a copy of the model-interface a distance in the z-directionabove the model-interface 804 that corresponds to the height for theextension segment 206; and at step 1212, defining a model of anextension segment 802 extending in the z-direction from themodel-interface 804 to the copy of the model-interface 804.

As shown in FIG. 12C, extending a model-interface 804 in the z-directionmay include, at step 1214, positioning the model-interface 804 at anelevation corresponding to a build plane 122 of an additivemanufacturing machine 104; at step 1216, determining a nominalextended-plane 1104 of a nominal model corresponding to a top surface ofthe nominal model, and positioning the nominal extended-plane 1104 ofthe nominal model a distance in the z-direction above themodel-interface 804 that corresponds to the height for the extensionsegment 206; and at step 1218, defining a model of an extension segment802 extending in the z-direction from the model-interface 804 to thenominal extended-plane 1104.

As shown in FIG. 12D, extending a model-interface 804 in the z-directionmay include, at step 1220, positioning the model-interface 804 at anelevation corresponding to a build plane 122; at step 1222, determininga slice elevation for an extended-plane 1104 of a model of an extensionsegment 802; at step 1224, determining a nominal extended-plane 1104 ina nominal model, the nominal extended-plane 1104 being at an elevationcorresponding to the slice elevation for the model of the extensionsegment 802; and at step 1226, positioning the nominal extended-plane1104 a distance in the z-direction above the model-interface 804 thatcorresponds to the slice elevation.

In some embodiments, extending a model-interface 804 in the z-directionmay include, at step 1228, transforming a nominal extended-plane 1104,providing a transformed extended-plane 1104. The transforming of thenominal extended-plane 1104 may be based at least in part on acomparison of the nominal extended-plane 1104 to the model-interface804. Additionally, or in the alternative, the transforming of thenominal extended-plane 1104 may be based at least in part on theposition of the nominal extended-plane 1104 above the model-interface804 relative to the height for the extension segment 206. Thetransforming at step 1228 may include one more transforming operations,including those shown in FIGS. 10A-10D, or any other transformingoperation, such as aligning, altering, modifying, contorting,distorting, deforming, correcting, adjusting, revising, straightening,tilting, rotating, bending, twisting, or editing, as well ascombinations of these.

The particular transforming operation(s) at step 1228 may be selectedbased at least in part on the comparison of the nominal extended-plane1104 and/or the position of the nominal extended-plane 1104. In someembodiments, a transforming operation may include a smoothing factor,which may be configured to provide a graduated transition from amodel-interface 804 to a transformed extended-plane 1104. For example,an extended-plane 1104 may have a perimeter that differs from amodel-interface perimeter 806, and the smoothing factor may beconfigured to provide a gradual transition therebetween. The smoothingfactor may temper the transformation by a prorated amount depending onthe z-directional location of the extended-plane 1104.

An extended-plane 1104 at a z-direction position that corresponds to theheight of the extension segment 206 may not be transformed, such thatthe model of the extension segment 802 may gradually transition alongthe z-direction from a model-interface 804 conforming to aworkpiece-interface 120 to an extended-plane 1104 conforming to the topsurface 858 of the nominal model 852. Additionally, or in thealternative, an extended-plane 1104 at a z-direction position betweenthe model-interface 804 and the top surface of the extension segment 808may be transformed with a smoothing factor applied to thetransformation, so as to provide a transformed extended-plane 1104conforming to a perimeter partly between that of the model-interface 804and that of the top surface of the nominal model 852. Also, in someembodiments, an extended-plane 1104 at a z-direction position thatcorresponds to the height of the extension segment 206 may betransformed, for example, to provide top surface 808 of an extensionsegment 206 that differs from a top surface of the nominal model.

Still referring to FIG. 12D, the step of extending a model-interface 804in the z-direction may be performed for any number of slices. As shownin FIG. 12D, an exemplary method 1200 may include, at step 1230,determining whether the model of the extension segment 802 may includeanother slice. The number of slices may be predetermined, such as basedon the intended height of the model of the extension segment 802 and az-directional slice interval. A z-directional slice interval may dependon the desired z-directional resolution of the model of the extensionsegment 802. When there is another slice, the exemplary method 1200 mayinclude repeating steps 1222 through 1230. When step 1230 indicates thatthere are no additional slices, the exemplary method 1200 may proceedwith step 1232, which provides for defining a model of an extensionsegment 802 extending in the z-direction from the model-interface 804through each nominal or transformed extended-plane 1104, with the modelextending to the height for the extension segment 206. The model of theextension segment 802 may be defined at step 1232 concurrently as, orsubsequently after, each extension-plane is determined, positioned,and/or transformed at steps 1224, 1226, and 1228.

Referring again to FIG. 9A, a model of a plurality of extension segments802 may be output at step 914, such as to an extension segment-CAD model800 as shown in FIG. 8A. Each of the models of the extension segments802 may include a model-interface 804 aligned in the z-direction to aninterface plane in the extension segment-CAD model 800. The interfaceplane in the extension segment-CAD model 800 may correspond to a buildplane 122 of an additive printing machine 104. In this way, a pluralityof extension segments 206 may be additively printed onworkpiece-interfaces 120 of respective workpieces 116 as part of thesame build with each extension segment 206 properly aligning in thez-direction with the build plane 122. Referring again to FIG. 4, anexemplary method 400 of additively printing an extension segment 206includes, at step 408 generating a print command based at least in parton a digital representation of a field of view 114 captured by thevision system. FIG. 7B, shows an exemplary method 750 of generating aprint command for a plurality of slices of one or more extensionsegments 206.

Now referring to FIG. 13, an exemplary print command 1300 for a slice ofa plurality of extension segments 206 is graphically depicted. As shownin FIG. 13, an exemplary print command 1300 for additively printing aslice of an extension segment 206 may include a plurality of scan paths1302 respectively corresponding to the slice. In an exemplaryembodiment, the print command 1300 may be for a slice that includes ascan path corresponding to the model-interface 804 of the plurality ofextension segments 206. Additional print commands 130 may be generatedfor each respective slice as described with reference to FIG. 7B. Thenumber of slices may depend on the size (e.g., height, thickness) of theextension segment(s) 206 in the extension segment-CAD model 800, as wellas the desired thickness of the layers of powder 126 or other materialthat may be used to additively print the extension segment(s) 206.

In exemplary embodiments, the extension segment-CAD model 800 mayinclude a model of a plurality of extension segments 802, in which atleast a first model of a first extension segment 802 differs from atleast a second model of a second extension segment 802. The first modelof the first extension segment 802 may conform to and may besubstantially congruent with a first workpiece-interface 120 of a firstworkpiece 116, and the second model of the second extension segment 802may conform to and be substantially congruent with a secondworkpiece-interface 120 of a second workpiece 116. The print command1300 may include a first scan path corresponding to a first slice of thefirst extension segment 206 and a second scan path corresponding to asecond slice of the second extension segment 206, and the first scanpath may differ from the second scan path. For example, the first scanpath may define a first extension segment perimeter and the second scanpath may define a second extension segment perimeter, in which the firstextension segment perimeter differs from the second extension segmentperimeter, such as in respect of curvature, surface area, and/orgeometry.

Now referring to FIGS. 14-19, exemplary pretreatments, methods ofdetermining and/or generating a pretreatment command, and methods ofpretreating a workpiece-interface 120 will be further described.

FIG. 14 shows an exemplary method 140 of generating a pretreatmentcommand, which may be performed, for example, as at step 414 in theexemplary method 400 of additively printing an extension segment 206shown in FIG. 4. An exemplary method 1400 may include, at step 1402,determining and/or generating a pretreatment-CAD model. Thepretreatment-CAD model may provide a two-dimensional or athree-dimensional model of the pretreatment region. When thepretreatment-CAD model provides a two-dimensional model of thepretreatment region, the exemplary method 1400 may proceed to step 1404,providing for determining a pretreatment region and a scan path and forthe extension segment-CAD model. When the pretreatment-CAD modelprovides a three-dimensional model of the pretreatment region, theexemplary method 1400 may proceed with step 1406, providing for slicingthe pretreatment-CAD model, and then step 1404, providing fordetermining a pretreatment region and a scan path for each slice of theextension segment-CAD model. After determining a pretreatment region anda scan path for a slice of the extension segment-CAD model at step 1404,the exemplary method 1400 may proceed with determining, at step 1408,whether there is another slice, and if so, the exemplary method 1400 mayproceed back to step 1404, providing for determining a pretreatmentregion and a scan path for a next slice of the pretreatment-CAD model.The exemplary method 1400 may end, at step 1410, when there are noadditional slices for which a pretreatment region and a scan path may bedetermined.

The number of slices in a pretreatment-CAD model may depend on thenature of the pretreatment to be provided. For example, in someembodiments a pretreatment-CAD model for a pretreatment that includesadditive-leveling may include more slices than a pretreatment-CAD modelfor melt-leveling or heat-conditioning. As another example, when apretreatment includes heat-conditioning or melt-leveling aworkpiece-interface without additive-leveling, the pretreatment-CADmodel may include only one slice, although such as pretreatment-CADmodel may include a plurality of slices. Further, while a pretreatmentthat includes additive-leveling may utilize a pretreatment-CAD modelthat includes a plurality of slices, additive-leveling may also beprovided using a pretreatment-CAD model that includes only one slice. Byway of example, a pretreatment-CAD model may include from 1 to 20slices, such as from 1 to 10 slices, such as from 1 to 5 slices, such asfrom 5 to 10 slices, or such as from 10 to 20 slices, depending on thenature of the pretreatment to be provided. In an exemplary embodiment, apretreatment-CAD model may include from 1 to 5 slices, such as from 1 to3 slices, or such as from 1 to 2 slices.

Now turning to FIGS. 15A-15R, exemplary pretreatment-CAD models 1500will be described. FIGS. 15A, 15D, 15G, 15J, 15M, and 15P and showexemplary digital representations of an aberrant workpiece-interface1502 obtained from a field of view 114 of a vision system 102. FIGS.15B, 15E, 15H, 15K, 15N, and 15Q show exemplary pretreatment-CAD models1500 respectively corresponding to the digital representations of theaberrant workpiece-interfaces 1502 shown in FIGS. 15A, 15D, 15G, 15J,15M, and 15P. The pretreatment-CAD models 1500 may include anadditive-leveling pretreatment, a melt-leveling pretreatment, and/or aheat-conditioning pretreatment. FIGS. 15C, 15F, 15, 15L, 15O, and 15Rshow exemplary pretreated workpiece-interfaces 1504 resulting frompretreating the respective aberrant workpiece-interfaces 120 shown inFIGS. 15A, 15D, 15G, 15J, 15M, and 15P according to the correspondingpretreatment-CAD models 1500 shown in FIGS. 15B, 15E, 15H, 15K, 15N, and15Q.

As shown in FIGS. 15A. 15D, 15G, and 15J, a workpiece-interface 120 mayinclude one or more congruent region 1506 and one or more aberrantregions 1508. The one or more congruent regions 1506 may exhibit anabsence of aberrant features. Alternatively, as shown in FIGS. 15M and15P, an aberrant region 1508 may encompass all or substantially all of aworkpiece-interface 120. When aberrant features are isolated to one ormore aberrant regions 1508, a pretreatment may be performed only on theaberrant regions 1508 of the workpiece-interface 120. Alternatively, apretreatment may be performed across all or substantially all of theworkpiece-interface 120. For example, when the aberrant regions 1508 arewidespread, it may be desirable to perform a pretreatment across all orsubstantially all of the workpiece-interface 120 rather than isolatingthe pretreatment to particular aberrant regions 1508. Additionally, orin the alternative, it may be desirable to perform a pretreatment acrossall or substantially all of the workpiece-interface 120, regardless ofwhether the aberrant regions 1508 are isolate or widespread, forexample, when the pretreatment may enhance the workpiece-interface 120as a whole such as when the pretreatment may provide a more congruentworkpiece-interface 120, may enhance the workpiece-interface 120generally, and/or when aberrant features may exist but that are notdetectable with the vision system 120 or that have not been detectedwith the vision system.

The absence of aberrant features in the one or more congruent regions1506 may be directly determined from a digital representation of theworkpiece-interface 120 obtained from a vision system 102, or theabsence of aberrant features may be inferentially determined, forexample, when aberrant features have not been directly determined in aregion or regions of the digital representation of theworkpiece-interface 120. The one or more aberrant regions 1508 mayexhibit one or more aberrant features. The presence of aberrant featuresin the one or more aberrant regions 1508 may be directly determined fromthe digital representation of the workpiece-interface 120, or thepresence of aberrant features may be inferentially determined, forexample, when an absence of aberrant features has not been directlydetermined from the digital representation of the workpiece-interface120.

FIG. 15B shows an exemplary pretreatment-CAD model 1500 determinedand/or generated for the aberrant workpiece-interface 1502 shown in FIG.15A. As shown, the pretreatment-CAD model 1500 may include amodel-interface perimeter 806 having substantial congruency with theworkpiece-interface perimeter 504 of the aberrant workpiece-interface1502, such that the pretreatment-CAD model 1500 may be configured toapply a pretreatment to all or substantially all of theworkpiece-interface 120. The pretreatment-CAD model 1500 shown in FIG.15B may be selected, for example, even though the aberrantworkpiece-interface 1502 shown in FIG. 15A may be determined to exhibitaberrant features (e.g., directly determined or inferentiallydetermined) only in one or more aberrant regions 1508.

FIG. 15C shows a pretreated workpiece-interface 1504 resulting frompretreating the aberrant workpiece-interface 1502 shown in FIG. 15Aaccording to the pretreatment-CAD model 1500 shown in FIG. 15B. Asshown, the pretreated workpiece-interface 1504 may include a pretreatedsurface having substantial congruency with the workpiece-interfaceperimeter 504, such that the pretreatment may be applied across all orsubstantially all of the workpiece-interface 120. The pretreatment mayinclude remediating aberrant features and/or enhancing one or morefeatures of the workpiece 116 and/or of the workpiece-interface 120 inpreparation for additively printing an extension segment on theworkpiece-interface 120.

FIG. 15E shows another exemplary pretreatment-CAD model 1500. Thepretreatment-CAD model 1500 shown in 15E may be determined and/orgenerated for the aberrant workpiece-interface 1502 shown in FIG. 15D.As shown in FIG. 15E, the pretreatment-CAD model 1500 may include amodel-interface perimeter 806 having substantial congruency with apretreatment region 1510 of the aberrant workpiece-interface 120. Thepretreatment region 1510 may be defined by a pretreatment-regionperimeter 1512. In some embodiments, the pretreatment-CAD model 1500 maybe configured to isolate the pretreatment to the aberrant regions 1508of the workpiece-interface 120. The pretreatment-CAD model 1500 shown inFIG. 15E may be selected, for example, when the aberrantworkpiece-interface 1502 shown in FIG. 15D may be determined to exhibitaberrant features (e.g., directly determined or inferentiallydetermined) only in one or more aberrant regions 1508.

FIG. 15F shows a pretreated workpiece-interface 1504 resulting frompretreating the aberrant workpiece-interface 1502 shown in FIG. 15Daccording to the pretreatment-CAD model 1500 shown in FIG. 15E. Asshown, the pretreated workpiece-interface 1504 may include a pretreatedsurface having substantial congruency with a pretreatment region 1510defined by a pretreatment-region perimeter 1512, such that thepretreatment may be isolated to the aberrant regions 1508 of theworkpiece-interface 120. The pretreatment may include remediatingaberrant features and/or enhancing one or more features of the workpiece116 and/or of the workpiece-interface 120 in preparation for additivelyprinting an extension segment on the workpiece-interface 120.

In some embodiments, the pretreatments shown in FIGS. 15C and 15F mayinclude additive leveling. For example, the aberrant regions 1508 shownin FIGS. 15C and 15F may exhibit skewness and/or a lower elevationrelative to the build plane 122 and/or relative to the congruent regions1506. In other embodiments, the pretreatment may include melt-leveling.For example, FIGS. 15G and 15J show exemplary aberrantworkpiece-interfaces 1502 with aberrant regions 1508 that exhibitskewness and/or a higher elevation relative to the build plane 122and/or relative to the congruent regions 1506. The aberrantworkpiece-interfaces 1502 shown in FIGS. 15G and 15J may receive apretreatment that includes melt-leveling according to pretreatment-CADmodels 1500 respectively shown in FIGS. 15H and 15K. However, it will beappreciated that the pretreatments shown in FIGS. 15C and 15F may alsoinclude melt-leveling in addition or as an alternative toadditive-leveling. Likewise, the pretreatments shown in FIGS. 15G and15J may also include additive-leveling in addition or as an alternativeto melt-leveling.

The exemplary pretreatment-CAD model 1500 shown in FIG. 15H determinedand/or generated for the aberrant workpiece-interface 1502 shown in FIG.15G, for example, so as to provide a model-interface perimeter 806having substantial congruency with the workpiece-interface perimeter 504of the aberrant workpiece-interface 120. The pretreatment-CAD model 1500shown in FIG. 15K may be determined and/or generated for the aberrantworkpiece-interface 1502 shown in FIG. 15J, for example, to provide amodel-interface perimeter 806 having substantial congruency with apretreatment region 1510 of the aberrant workpiece-interface 120 andthereby isolate the pretreatment to the aberrant regions 1508 of theworkpiece-interface 120. The pretreatment-CAD model 1500 shown in FIG.15H may be selected, for example, even though the aberrantworkpiece-interface 1502 shown in FIG. 15G may be determined to exhibitaberrant features (e.g., directly determined or inferentiallydetermined) only in one or more aberrant regions 1508. Thepretreatment-CAD model 1500 shown in FIG. 15K may be selected, forexample, when the aberrant workpiece-interface 1502 shown in FIG. 15DJmay be determined to exhibit aberrant features (e.g., directlydetermined or inferentially determined) only in one or more aberrantregions 1508.

FIG. 15I shows a pretreated workpiece-interface 1504 resulting from apretreatment applied to the aberrant workpiece-interface 1502 shown inFIG. 15G according to the pretreatment-CAD model 1500 shown in FIG. 15H.The pretreatment may provide a pretreated workpiece-interface 1504 thatincludes a pretreated surface having substantial congruency with theworkpiece-interface perimeter 504. FIG. 15L shows a pretreatedworkpiece-interface 1504 resulting from pretreating the aberrantworkpiece-interface 1502 shown in FIG. 15J according to thepretreatment-CAD model 1500 shown in FIG. 15E, providing a pretreatedsurface having substantial congruency with a pretreatment region 1510defined by a pretreatment-region perimeter 1512 so as to isolate thepretreatment to the aberrant regions 1508 of the workpiece-interface120. The pretreatments shown in FIGS. 15I and/or 15L may includeremediating aberrant features and/or enhancing one or more features ofthe workpiece 116 and/or of the workpiece-interface 120 in preparationfor additively printing an extension segment on the workpiece-interface120.

While the aberrant workpiece-interfaces 1502 in the embodiments shown inFIGS. 15A, 15D, 15G, and 15J include one or more aberrant regions 1508,in other embodiments, an aberrant workpiece-interface 1502 may includewidespread aberrant regions 1508 and/or the aberrant region 1508 may bedirectly or inferentially determined to encompass all or substantiallyall of the workpiece-interface perimeter 504. For example, FIGS. 15M and15P show exemplary embodiments of an aberrant workpiece-interfaces 1502with the region defined by the workpiece-interface perimeter 504 beingthe aberrant region 1508. As shown in FIGS. 15N and 15Q, apretreatment-CAD model 1500 may include a model-interface perimeter 806having substantial congruency with the workpiece-interface perimeter 504of the respective aberrant workpiece-interface 120, such that thepretreatment-CAD model 1500 may be configured to apply a pretreatment toall or substantially all of the workpiece-interface 120. FIG. 15N showsa pretreatment-CAD model 1500 configured to provide a pretreatment thatincludes additive-leveling, and FIG. 15O shows a pretreatedworkpiece-interface 1504 resulting from pretreating the aberrantworkpiece-interface 1502 shown in FIG. 15M according to thepretreatment-CAD model 1500 shown in FIG. 15N. FIG. 15Q shows apretreatment-CAD model 1500 configured to provide a pretreatment thatincludes melt-leveling, and FIG. 15R shows a pretreatedworkpiece-interface 1504 resulting from pretreating the aberrantworkpiece-interface 1502 shown in FIG. 15P according to thepretreatment-CAD model 1500 shown in FIG. 15Q. It will be appreciatedthat the pretreatment shown in FIG. 15O may also include a melt-levelingpretreatment and/or a heat-conditioning pretreatment, and that thepretreatment shown in FIG. 15R may also include an additive-levelingpretreatment and/or a heat-conditioning pretreatment.

Now referring to FIGS. 16A and 16B, exemplary workpieces 116 having anaberrant workpiece-interface 1502 and corresponding workpieces having apretreated workpiece-interface 1504 will be discussed. FIG. 16A shows anexemplary digital representation of a plurality of workpieces 116 havingan aberrant workpiece-interface 1502. The digital representation may beobtained using the vision system 102, for example, as described withreference to FIGS. 6A and 6B. As shown, a scratch coating of powder 126has been applied to the plurality of workpieces, partially covering someof the aberrant workpiece-interfaces 1502. In some embodiments, thepowder 126 may cover aberrant regions 1508 of the aberrantworkpiece-interfaces 1502 that have an elevation below that of thescratch coating. The portions of the aberrant workpiece-interfaces 1502exposed above the powder may be congruent regions 1506 and/or aberrantregions 1508. While all of the workpiece-interfaces 120 shown in FIG.16A are identified as aberrant workpiece-interfaces 1502, sometimesthere may be workpiece-interfaces that do not include an aberrant region1508.

All or a subset of the workpiece-interfaces 120 in a digitalrepresentation of a field of view 114 may be pretreated according to apretreatment-CAD model. The pretreatment-CAD model may include aplurality of models corresponding to respective ones of the plurality ofworkpiece-interfaces 120. The respective models within thepretreatment-CAD model may differ as between respectiveworkpiece-interfaces 120, for example, so as to apply a customizedpretreatment to respective ones of the workpiece-interfaces 120.Alternatively, a pretreatment-CAD model may include a plurality ofmodels differing only in respect of their coordinates, so as to apply acommon pretreatment as between respective ones of the plurality ofworkpiece-interfaces 120. However, even when the models in apretreatment-CAD differ only in respect of their coordinates, apretreatment resulting from such a pretreatment-CAD model may differ asbetween respective ones of the workpiece-interfaces 120. For example,with a scratch coating of powder 126 applied as shown in FIG. 16A, apretreatment-CAD model may apply an additive-leveling pretreatment toportions of the aberrant workpiece-interface 1502 (e.g., congruentregions 1606 or aberrant regions 1508) covered by the scratch coating ofpowder 126, while portions of the aberrant workpiece-interface 1502protruding above the scratch coating of powder 126 (e.g., congruentregions 1506 or aberrant regions 1508) may receive a melt-levelingpretreatment.

In some embodiments, the pretreatment-CAD model need not distinguishbetween the portions of the aberrant workpiece-interface 1502 that areto receive an additive-leveling pretreatment and the portions of theworkpiece-interface 1502 that are to receive a melt-levelingpretreatment. Instead, those portions of the aberrantworkpiece-interface 1502 covered by the scratch coating of powder 126may receive an additive-leveling pretreatment while those portions ofthe aberrant workpiece-interface 1502 protruding from the scratchcoating of powder 126 may receive a melt-leveling pretreatment,regardless of where transitions may exist between portions covered bythe scratch coating and portions protruding from the scratch coating.Alternatively, in some embodiments an additive-leveling pretreatment maybe applied specifically to the aberrant regions 1508 covered by thescratch coating and/or a melt-leveling pretreatment may be appliedspecifically to the aberrant regions 1508 protruding from the scratchcoating.

FIG. 16B shows an exemplary digital representation of a plurality ofworkpieces 116 after having a pretreatment applied thereto such that theworkpieces have a pretreated workpiece-interface 1504. The pretreatedworkpiece-interfaces 1504 shown in FIG. 16B may reflect a pretreatmentapplied to the aberrant workpiece-interfaces 1502 shown in FIG. 16A. Asshown, the pretreated workpiece-interfaces 1504 may have a congruentregion 1506 substantially congruent with the workpiece-interfaceperimeter 504. For example, the pretreated workpiece-interfaces 1504 maybe substantially level with a scratch coating of powder 126 as a resultof an additive-leveling and/or melt-leveling pretreatment.

Now turning to FIG. 17, an enlarged view of an exemplary pretreatedworkpiece-interface 1504 is shown. The pretreated workpiece-interfacemay include contour lines 1700 resulting from the scan path of theenergy source 142. The contour lines 1700 may reflect additive-leveling,melt-leveling, and/or heat-conditioning, reflecting one or more aberrantfeatures having been remediated and/or one or more features of theworkpiece-interface 120 having been enhanced. For example, the contourlines 1700 may enhance bonding between the workpiece 116 and anextension segment 206 additively printed on the workpiece-interface 120following pretreatment.

Now turning to FIGS. 18A and 18B, exemplary methods of determiningand/or generating a pretreatment-CAD model will be described. As shownin FIG. 18A, an exemplary method 1850 of generating a pretreatment-CADmodel may be performed for each of a plurality of workpieces 116. Anexemplary method 1850 may include, at step 1852, determining in alibrary-CAD model, a nominal model-interface 854 traversing a nominalmodel corresponding to a respective one of the plurality of workpieces116. The nominal model may include a model of a nominal component 204,such as a model of a component 204 from which the workpieces 116 mayhave originated. The workpieces 116 may, however, differ from acomponent 204 having been additively manufactured according to thenominal model, for example, because of damage or wear incurred by theworkpieces 116 as a result of the environment with which the component204 was used, and/or from a subtractive modification performed toprepare the workpiece 116 for an extension segment 206 to be additivelyprinted thereon. The nominal model may additionally or alternativelyinclude a model of a nominal workpiece, such as a nominal model of aworkpiece 116 produced by subjecting a nominal component 204 to asubtractive modification process to provide a workpiece-interface 120.The nominal model may additionally or alternatively include a model of anominal pretreatment region 1510, such as a nominal model of apretreatment region 1510 corresponding to a nominal workpiece 116.

Determining a nominal model-interface 854 may include determining aplane traversing the library-CAD model at a determined height. Thedetermined height may correspond to a height of an expected location ofa workpiece-interface 120 for a nominal workpiece 116. By way ofexample, a library-CAD model may include a model of a nominal component204 corresponding to the workpiece 116, and the workpiece 116 may havebeen subjected to a subtractive modification, such as to provide aworkpiece-interface 120. An expected location of a workpiece-interface120 may be determined based at least in part on the nature of thesubtractive modification, such as based on an expected amount ofmaterial removed or a resulting change in height of the workpiece 116 asa result of the subtractive modification.

Additionally, or in the alternative, the determined height maycorrespond to a height of a workpiece-interface 120 as determined from adigital representation of the workpiece 116. The height of aworkpiece-interface 120 may be measured based at least in part on one ormore dimensions of the workpiece 116 obtained from the digitalrepresentation of the workpiece, and a nominal model-interface 854 maybe determined based at least in part on the measured height.Additionally, or in the alternative, the height of theworkpiece-interface 120 may be measured based at least in part one ormore dimensions of a workpiece alignment system 200 captured in a fieldof view 114. For example, a height of the workpiece-interface 120 may bedetermined based at least in part on the height of a workpiece shoe 214,or based at least in part on a difference between the height of theworkpiece-interface 120 and the height of a workpiece shoe 214, or basedat least in part on a difference between the height of theworkpiece-interface 120 and the height of the build plate 118.

In some embodiments, a nominal model-interface 854 may be determinedusing a best-fit algorithm. Determining the nominal model-interface 854traversing the library-CAD model 850 may include determining a planetraversing the library-CAD model that meets a metric associated with abest-fit algorithm applied with respect to the digital representation ofthe workpiece-interface 120. The best-fit algorithm may compare one ormore planes traversing the library-CAD model to the digitalrepresentation of the workpiece-interface 120 until a compared planesatisfies the best-fit metric. The nominal model-interface 854 may bedetermined based at least in part on a plane that satisfies the best-fitmetric. For example, a plane that satisfies the best-fit metric may bedetermined to be the nominal model-interface 854.

Still referring to FIG. 18A, an exemplary method 1850 of determiningand/or generating a pretreatment-CAD model may include, at step 1854,comparing the nominal model-interface 854 of the library-CAD model to adigital representation of the workpiece-interface 120 of the respectiveones of the plurality of workpieces 116. The digital representation mayhave been previously or concurrently obtained using a vision system 102that has a field of view 114 including the workpiece-interface 120 ofthe respective one of the plurality of workpieces 116. The comparisonmay be performed using an image matching algorithm. In some embodiments,comparing the nominal model-interface 854 to the digital representationof the workpiece-interface 120 may include, at step 1856, determiningwhether the nominal model-interface 854 and the digital representationof the workpiece-interface 120 sufficiently match one another. However,in some embodiments a matching step 1856 need not be included.

When included, a matching step 1856 may include comparing one or morecoordinates of the nominal model-interface 854 with one or morecoordinates of the digital representation of the workpiece-interface 120and determining one or more differences therebetween. The comparing step1854 may additionally or alternatively include comparing one or morecoordinates of the one or more registration points 202 with acorresponding one or more coordinates of the nominal model-interface 854of the library-CAD model and determining one or more differencestherebetween. The registration points 202 may correspond to locations ofrespective ones of a plurality of workpieces 116 onto which respectiveones of a plurality of extension segments 206 are to be additivelyprinted using the additive manufacturing machine 104. The comparing step1854 and the matching step 1856 may be performed separately or togetheras part of the same step. In some embodiments, the matching step 1856may determine whether there is a partial match, a close match, or nomatch between the nominal model-interface 854 and theworkpiece-interface 120. Alternatively, the matching step 1856 maydetermine whether there is any match (e.g., at least a partial match),or no match between the nominal model-interface 854 and theworkpiece-interface 120.

When the matching step 1856 determines that there is at least a partialmatch between the nominal model-interface 854 and theworkpiece-interface 120, the exemplary method 1850 may proceed to step1858, providing for generating a model of a pretreatment region 1510based at least in part on the nominal model-interface 854, with themodel of the pretreatment region 1510 configured to expose theworkpiece-interface 120 of the respective one of the plurality ofworkpieces 116 to a pretreatment.

When the matching step 1856 determines that there is not at least apartial match between the nominal model-interface 854 and theworkpiece-interface 120, the exemplary method 1850 may return to step1852 so as to determine a different nominal model-interface 854 and tocompare the different nominal model-interface 854 to the digitalrepresentation of the workpiece-interface 120. The different nominalmodel-interface 854 may be selected form the same library-CAD model or adifferent library-CAD model.

In some embodiments, the matching step 1856 may include determiningwhether there is more than a partial match, such as a close matchbetween the nominal model-interface 854 and the workpiece-interface 120.When the matching step 1856 determines that there is a close matchbetween the nominal model-interface 854 and the workpiece-interface 120,the exemplary method 1850 may include, at step 1860, selecting thenominal model-interface 854 and/or at least a three-dimensional portionof the nominal model from the library-CAD model based at least in parton the comparison. For example, the comparison may determine that theselected nominal model-interface 854 and/or the nominal model from thelibrary-CAD model conforms to the digital representation of theworkpiece-interface 120 of the respective one of the plurality ofworkpieces 116, such that the selected nominal model-interface 854 maybe aligned with coordinates that correspond to the digitalrepresentation of the workpiece-interface 120, and/or the selectednominal model-interface 854 may be substantially congruent with thedigital representation of the workpiece-interface 120. In variousexemplary embodiments, step 1860 may include selecting the nominal modelas a whole for a respective workpiece, selecting a three-dimensionalportion of the nominal model for a respective workpiece 116 (which mayinclude the nominal model-interface 854), and/or selecting only thenominal model-interface 854 for the respective workpiece 116.

When a nominal model or a three-dimensional portion thereof is selectedat step 1858, the exemplary method 1850 may include determining apretreatment-CAD model from the library-CAD model. For example, alibrary-CAD model that includes a nominal pretreatment region 1510 maybe determined to sufficiently match a workpiece-interface 120 such thata workpiece 116 may be subjected to a pretreatment that conforms to theworkpiece-interface 120 without requiring transforming or extending thenominal model-interface 854 at steps 1860, 1862. In other embodiments,the exemplary method 1850 may proceed with generating a model of apretreatment region 1510 at step 1858, for example, based at least inpart on a library-CAD model that includes a model of a nominal component204, a model of a nominal workpiece 116, or a model of a nominalextension segment 206. The model of the pretreatment region 1510generated at step 1858 may be configured to expose a workpiece-interface120 of a respective one of the plurality of workpieces 116 to apretreatment.

In exemplary methods 1850 that do not include a matching step 1856, anexemplary method may proceed to generating a model of a pretreatmentregion 1510 based at least in part on the nominal model-interface 854 atstep 1858 after having compared the nominal model-interface 854 to thedigital representation of the workpiece-interface 120 at step 1854. Insome embodiments, steps 1854 and 1858 may be combined into a singlestep, such that comparing the nominal model-interface 854 to the digitalrepresentation of the workpiece-interface 120 may be part of the processof generating a model of a pretreatment region 1510 based at least inpart on the nominal model-interface 854.

After having generated and/or selected a model of a pretreatment region1510 at steps 1858, 1860, an exemplary method 1850 may ascertain, atstep 1862, whether the plurality of workpieces 116 includes anotherworkpiece 116. When there is another workpiece, the exemplary method1850 may include repeating the determining step 1852 and subsequentsteps through to step 1862. When step 1862 indicates that there are noadditional workpieces 116, the exemplary method 1850 may proceed withstep 1864, which provides for outputting a model of a plurality ofpretreatment regions 1510 respectively correspond to theworkpiece-interfaces 120 of the respective ones of the plurality ofworkpieces 116. The model may be a pretreatment-CAD model, and the modelmay be based at least in part on the selecting and/or transforming ofthe nominal model-interface 854 and/or the nominal model from thelibrary-CAD model.

The model of the plurality of pretreatment regions 1510 may be output atstep 1864 concurrently as, or subsequently after, each additionalpretreatment region 1510 is generated and/or selected at steps 1858,1860. In some embodiments, outputting the model may include stitchingtogether a plurality of models, such as models having been respectivelyselected and/or transformed and generated for respective ones of theplurality of workpieces 116. While an exemplary method 1850 ofdetermining and/or generating a pretreatment-CAD model has beendescribed with respect to a plurality of pretreatment regions 1510, itwill be appreciated that a pretreatment-CAD model may also be determinedand/or generated for a single pretreatment region 1510. For example, theexemplary method 1850 may be performed for a single workpiece 116.

Referring now to FIG. 18B, exemplary embodiments of generating a modelof a pretreatment region 1510 at step 1858 (FIG. 18A) will be furtherdescribed. When generating a model of a pretreatment region 1510, one ormore steps shown in FIG. 18B may be performed, and the particular stepsperformed may depend at least in part on whether the nominalmodel-interface 854 provides a partial match or a close match at step1856 (FIG. 18A), and/or whether the nominal model-interface 854 or atleast a three-dimensional portion of the nominal model are selected atstep 1860 (FIG. 18A).

As shown in FIG. 18B, generating a model of a pretreatment region 1510at step 1858 may include an extracting step 1866, such that apretreatment region 1510 may be generated based at least in part on anominal model-interface 854 and/or a three-dimensional portion of anominal model corresponding to the nominal model-interface 854.Alternatively, the extracting step 1866 may be omitted, for example,such that a nominal model may itself be configured to subject aworkpiece-interface 120 to a pretreatment. The step 1858 of generating amodel of a pretreatment region 1510 may additionally or alternativelyinclude a transforming step 1868, such that a nominal model-interface854 may be conformed to the digital representation of theworkpiece-interface 120. Alternatively, the transforming step 1868 maybe omitted, for example, when a nominal model-interface 854 alreadyconforms to the digital representation of the workpiece-interface 120.The step 1858 of generating a model of a pretreatment region 1510 mayfurther additionally or alternatively include an extending step 1870,such that a nominal model-interface 854 or a transformed model-interface804 may be extended so as to provide a three-dimensional pretreatmentregion 1510. Alternatively, the extending step 1870 may be omitted, forexample, when generating a three-dimensional model of a pretreatmentregion 1510 from a three-dimensional portion of the nominal model.

In some embodiments, at step 1866, generating a model of a pretreatmentregion 1510 may optionally include extracting from a nominal model basedat least in part on the comparison at step 1854, 1856, a nominalmodel-interface 854 and/or a three-dimensional portion of the nominalmodel corresponding to the nominal model-interface 854. The extractingstep may be performed following the comparing step 1854, following thematching step 1856, or following the selecting step 1860.

In some embodiments, generating a model of a pretreatment region 1510may optionally include, at step 1868, transforming a nominalmodel-interface 854 based at least in part on the comparison at step1854, 1856, so as to provide a transformed model-interface 804conforming to the digital representation of the workpiece-interface 120of the respective one of the plurality of workpieces 116. Thetransforming step may include one more transforming operations,including aligning, altering, modifying, contorting, distorting,deforming, correcting, adjusting, revising, straightening, tilting,rotating, bending, twisting, or editing, as well as combinations ofthese. The particular transforming operation(s) may be selected based atleast in part on the comparison such that the transforming operation(s)conforms the nominal model-interface 854 to the digital representationof the workpiece-interface 120.

The transforming step 1868 may be performed following the comparing step1854 and/or following the matching step 1856. Additionally, or in thealternative, the transforming step 1868 may be performed following theextracting step 1866. An exemplary method 1850 may include extractingthe nominal model-interface 854 from the nominal model and thenproceeding to step 1868, providing for transforming the nominalmodel-interface 854 based at least in part on the comparison at step1854, 1856, so as to provide a transformed model-interface 804conforming to the digital representation of the workpiece-interface 120of the respective one of the plurality of workpieces 116.

In some embodiments, generating a model of a pretreatment region 1510may optionally include, at step 1870, extending the transformedmodel-interface 804, so as to provide a three-dimensional pretreatmentregion 1510. Step 1870 may be performed after having transformed thenominal model-interface 854 at step 1868. Alternatively, in someembodiments, the extending step 1870 may be combined with thetransforming step 1868.

Further additionally, or in the alternative, step 1868 may follow step1860 (FIG. 18A), providing for extending a nominal model-interface 854that has been selected at step 1860. For example, when a nominalmodel-interface 854 closely matches a digital representation of aworkpiece-interface 120, such as may be determined at step 1856, thetransforming step 1868 may be omitted from the step of generating amodel of a pretreatment region 1510 at step 1858. Regardless of whetherthe nominal model-interface 854 is transformed at step 1868 or selectedat step 1860 with the transforming step 1868 being omitted, theextension segment 206 resulting from the extending step 1862 may beconfigured to be additively printed on the workpiece-interface 120 ofthe respective one of the plurality of workpieces 116.

In an exemplary embodiment, generating a model of a pretreatment region1510 at step 1858 may include, at step 1866, extracting from the nominalmodel based at least in part on the comparison of the nominalmodel-interface 854 to a digital representation of workpiece-interface120; at step 1868, transforming the nominal model-interface 854 based atleast in part on the comparison so as to provide a transformedmodel-interface 804 conforming to the digital representation of theworkpiece-interface 120; and at step 1870, extending the transformedmodel-interface 804 so as to provide a model of a pretreatment region1510 that conforms to the workpiece-interface 120 of a workpiece 116.

Referring still to FIG. 18B, in another embodiment, the step 1858 ofgenerating a model of a pretreatment region 1510 may include, at step1866, extracting from the nominal model a three-dimensional portion ofthe nominal model. The three-dimensional portion may correspond to thenominal model-interface 854. For example, the three-dimensional portionmay include a portion of the nominal model above and/or below thenominal model-interface 854 and may include the nominal model-interface854. The three-dimensional portion of the nominal model below thenominal-model interface 854 may correspond to at least a portion of theworkpiece-interface 120 to be subjected to additive leveling. Thethree-dimensional portion of the nominal model above the nominal-modelinterface 854 may correspond to a pretreatment layer of powder 126applied to the workpiece-interface in connection with the pretreatment.

In some embodiments, generating a model of a pretreatment region 1510may optionally include, at step 1872, transforming a three-dimensionalportion of a nominal model corresponding to a nominal model-interface854 based at least in part on the comparison at step 1854, 1856, so asto provide a model of a pretreatment region 1510 conforming to thedigital representation of the workpiece-interface 120 of the respectiveone of the plurality of workpieces 116. The model of the pretreatmentregion 1510 may be configured to expose the workpiece-interface 120 ofthe respective one of the plurality of workpieces 116 to a pretreatment.The three-dimensional portion of the nominal model transformed at step1872 may include a three-dimensional portion extracted at step 1866 orat least a three-dimensional portion of a nominal model selected at step1860 (FIG. 18A). In some embodiments, the at least a three-dimensionalportion of a nominal model selected at step 1860 may include the nominalmodel as a whole, such as when the nominal model is a model of a nominalpretreatment region 1510.

The step 1872 of transforming a three-dimensional portion may includetransforming the nominal model-interface 854 of the three-dimensionalportion, and may include one more transforming operations, includingaligning, altering, modifying, contorting, distorting, deforming,correcting, adjusting, revising, straightening, tilting, rotating,bending, twisting, or editing, as well as combinations of these. Theparticular transforming operation(s) at step 1872 may be selected basedat least in part on the comparison such that the transformingoperation(s) conforms the nominal model-interface 854 to the digitalrepresentation of the workpiece-interface 120. Additionally, or in thealternative, the step 1872 of transforming a three-dimensional portionmay include extending the nominal model-interface 854 so as to provide apretreatment region 1510 conforming to the digital representation of theworkpiece-interface 120 of the respective one of the plurality ofworkpieces 116.

Now referring to FIG. 19, an exemplary pretreatment command 1900 forpretreating a plurality of aberrant workpiece-interfaces 1502 isgraphically depicted. As shown in FIG. 19, a pretreatment command 1900for pretreating a plurality of aberrant workpiece-interfaces 1502 mayinclude a plurality of scan paths 1902 respectively corresponding to theplurality of aberrant workpiece-interfaces 1502. In an exemplaryembodiment, the pretreatment command 1900 includes a scan pathcorresponding to a model-interface 804 of a plurality ofworkpiece-interfaces 120 (e.g., a plurality of nominalworkpiece-interfaces 120 or a plurality of aberrant workpiece-interfaces1502). Additional pretreatment commands 1900 may be generated for eachrespective slice of a pretreatment as described with reference to FIG.14.

In exemplary embodiments, the pretreatment-CAD model 1500 may include amodel of a plurality of pretreatment commands 1900, in which at least afirst model of a first pretreatment region 1510 differs from at least asecond model of a second pretreatment region 1510. The first model ofthe first pretreatment region 1510 may conform to and may besubstantially congruent with a first workpiece-interface 120 (e.g., afirst aberrant workpiece-interface 1502) of a first workpiece 116, andthe second pretreatment region 1510 may conform to and be substantiallycongruent with a second workpiece-interface 120 (e.g., a second aberrantworkpiece-interface 1502) of a second workpiece 116. The pretreatmentcommand 1900 may include a first scan path corresponding to a firstslice of the first pretreatment region 1510 and a second scan pathcorresponding to a second slice of the second pretreatment region 1510,and the first scan path may differ from the second scan path. Forexample, the first scan path may define a first pretreatment region 1510perimeter and the second scan path may define a second pretreatmentperimeter, in which the first pretreatment perimeter differs from thesecond pretreatment region 1510 perimeter, such as in respect ofcurvature, surface area, and/or geometry.

Now referring to FIGS. 20-26, in some embodiments, an exemplary additivemanufacturing system 100 may be configured to perform a calibrationadjustment so as to prevent or mitigate discrepancies, biases,misalignments, calibration errors, or the like which may otherwise arisefrom time to time as between one or more aspects of the additivemanufacturing system 100. For example, a calibration adjustment may beconfigured to prevent or mitigate discrepancies, biases, misalignments,calibration errors, or the like between a vision system 102 and anadditive manufacturing machine 104, between a vision system 102 and oneor more CAD models (e.g., extension segment-CAD models and/orpretreatment-CAD models) generated based at least in part on one or moredigital images obtained using the vision system 102, or between one ormore CAD models and an additive manufacturing machine 104, as well ascombinations of these.

A calibration-CAD model may be utilized to calibrate an additivemanufacturing system 100, such as by performing a calibrationadjustment. FIG. 20 shows an exemplary calibration-CAD model 2000. Thecalibration-CAD model 2000 includes one or more model calibration marks2002. The one or more model calibration marks 2002 may respectively takethe form of or include a model of a registration point 202. For example,a model calibration mark 2002 may include a dot or other mark thatdefines a model of a registration point 202. The one or more modelcalibration marks 2002 may be respectively located at CAD-modelcoordinates corresponding respective ones of a plurality of registrationpoints 202 (FIGS. 2A and 2B). The registration points 202 maycorresponding to locations where respective ones of a plurality ofworkpieces 116 are to be situated when additively printing on therespective workpiece-interfaces 120 thereof.

One or more workpiece docks 210 may be respectively configured to securea plurality of workpieces 116 to a build plate 118, and the registrationpoints 202 may provide an indication of where the workpieces 116 areexpected to be located when secured to the build plate 118 and installedin the vision system 102 and/or the additive manufacturing machine 104.A calibration-CAD model 2000 may be utilized by an additivemanufacturing machine 104 to additively print model calibration marks2002 at locations corresponding to the registration points 202, such asat locations where the workpieces 116 are expected to be located whensecured to a build plate 118. For example, registration points 202represented by model calibration marks 2002 may correspond to locationsof one or more workpiece docks of a build plate 118.

In an exemplary embodiment, respective ones of the plurality of modelcalibration marks 2002 may have CAD model-coordinates that correspond torespective ones of the plurality of registration points 202. The modelcalibration marks 2002 may include a geometric shape or pattern, and atleast a portion of the geometric shape or pattern may have CADmodel-coordinates that correspond to a respective registration point202. In yet another exemplary embodiment, a model calibration mark 2002may include a contour corresponding to a perimeter of a model of anextension segment 802, such as a model-interface perimeter 806, and thecontour may have CAD model-coordinates corresponding to a location of aworkpiece 116 onto which an extension segment 206 may be additivelyprinted based on the model of the extension segment 802.

FIG. 21 shows an exemplary calibration surface 2100 that includes aplurality of printed calibration marks 2102 that were printed on thecalibration surface 2100 using the additive manufacturing machine 104.The printed calibration marks 2102 may have been printed on thecalibration surface 2100 based at least in part on a calibration-CADmodel 2000, such as the calibration-CAD model 2000 shown in FIG. 20. Thecalibration surface 2100 may include a build plate 118, and/or acalibration sheet applied to a build plate 118. An exemplary calibrationsheet may include transfer paper, carbon paper, or other materialsuitable for the additive manufacturing machine 104 to print thecalibration marks 2102 thereon. In an exemplary embodiment, the printedcalibration marks 2102 may be printed using an additive manufacturingtool such as a laser, but without utilizing powder 126 or other additivematerial. For example, an additive manufacturing machine 104 may includean energy source 142 such as a laser configured to additively print theplurality of extension segments 206 by marking the calibration surface2100 using the energy source 142.

FIG. 22 shows an exemplary digital representation 2200 of a field ofview 114 that includes a plurality of digitally represented calibrationmarks 2202 having been obtained using a vision system 102. The digitalrepresentation 2200 of the digitally represented calibration marks 2202in the field of view 114 may be determined using an edge detectionalgorithm. An exemplary edge detection algorithm may determine thedigitally represented calibration marks 2202 by determining pixelswithin the digital representation 2200 of the field of view 114 thathave discontinuities, such as changes in brightness or contrast. Asshown in FIG. 22, the digital representation 2200 of the field of view114 may be compared to calibration-CAD model 2000. For example,respective ones of a plurality of digitally represented calibrationmarks 2202 may be compared to respective ones of a correspondingplurality of model calibration marks 2002.

FIG. 23 shows an exemplary comparison table 2300 illustrating anexemplary comparison of respective ones of a plurality of digitallyrepresented calibration marks 2202 to corresponding respective ones of aplurality of model calibration marks 2002. As shown in FIG. 23, such acomparison may include determining nominal coordinates 2302 for themodel calibration marks 2002 and determining measured coordinates 2304for the digitally represented calibrations marks 2202. Such a comparisonmay additionally include determining a system offset 2306, such as adifference between respective digitally represented calibrations mark2202 and corresponding model calibration marks 2002. Comparison data maybe obtained for each model calibration mark 2002, such as for eachcorresponding registration point 202.

A system offset 2306 may indicate a discrepancy, bias, misalignment,calibration error, or the like. A calibration adjustment may beperformed responsive to the comparison. The calibration adjustment maybe applied to any aspect of the additive manufacturing system 100,including the vision system 102, the additive manufacturing machine 104,or a control system 106. Additionally, or in the alternative, acalibration adjustment may be applied to one or more CAD models,including a library-CAD model and/or an extension segment-CAD model 800.For example, a calibration adjustment applied to a CAD model may beconfigured to align coordinates of the CAD model with coordinates of theadditive manufacturing system 100, such as vision system coordinatesand/or additive manufacturing machine coordinates. The calibrationadjustment may be applied so as to any one or more of the modelcalibration marks 2002 so as to align each model calibration mark 2002with a corresponding registration point 202. For example, a calibrationadjustment may be applied as to a model calibration mark 2002 when thesystem offset 2306 exceeds a threshold offset value.

Exemplary results of a calibration adjustment are schematicallyillustrated in FIGS. 24A-24C. FIG. 24A shows an exemplary digitalrepresentation 2400 of a workpiece-interface 120 obtained from a visionsystem 102 before calibration 2402 and after calibration 2404, such asfor a calibration adjustment applied to the vision system 102. FIG. 24Bshows an exemplary location of an extension segment 2410 additivelyprinted using an additive manufacturing machine 104 before calibration2412 and after calibration 2414, such as for a calibration adjustmentapplied to the additive manufacturing machine 104. FIG. 24C shows anexemplary location of a model of an extension segment 2420 in anextension-segment CAD model before calibration 2422 and aftercalibration 2424, such as for a calibration adjustment applied to theextension-segment CAD model.

Now referring to FIG. 25, exemplary methods of calibrating an additivemanufacturing system 100 will be described. An exemplary method 2500 mayinclude, at step 2502, comparing a digital representation of one or moredigitally represented calibration marks 2202 to a calibration-CAD model2000. The calibration-CAD model 2000 may include one or more modelcalibration marks 2002. The digital representation of the one or moredigitally represented calibration marks 2202 may have been obtainedusing a vision system 102, and the one or more printed calibration marks2102 may have been printed on a calibration surface 2100 according tothe calibration-CAD model 2000 using an additive manufacturing machine104. In some embodiments, the exemplary method 2500 may includeobtaining the digital representation of the one or more digitallyrepresented calibration marks 2202 using the vision system 102.

One or more calibration adjustments may be applied responsive to step2502. For example, in some embodiments, an exemplary method 2500 mayinclude, at step 2504, applying a calibration adjustment to one or moreCAD models based at least in part on the comparison. The calibrationadjustment may align the one or more CAD models with one or morecoordinates of the additive manufacturing system 100, such as visionsystem coordinates and/or additive manufacturing machine coordinates.For example, the calibration adjustment may align the coordinates of oneor more model calibration marks 2002 with coordinates of the additivemanufacturing machine 104. Additionally, or in the alternative, anexemplary method 2500 may include, at step 2506, applying a calibrationadjustment to the additive manufacturing system 100 based at least inpart on the comparison. The calibration adjustment applied to theadditive manufacturing system 100 may be configured to align one or morecoordinates of the vision system 102 with one or more coordinates of theadditive manufacturing machine 104.

In an exemplary embodiment, a method 2500 of calibrating an additivemanufacturing system 100 may include printing one or more modelcalibration marks 2002 on a calibration surface 2100 according to acalibration-CAD model 2000 using an additive manufacturing machine 104.The model calibration marks 2002 may be printed on the calibrationsurface 2100 at a plurality of registration points 202 according to thecalibration-CAD model 2000. The registration points 202 may haveCAD-model coordinates respectively corresponding to locations whererespective ones of a plurality of workpieces 116 are to be situated whenadditively printing respective ones of a plurality of extension segments206 onto the respective ones of the plurality of workpieces 116.

The digital representation of the digitally represented calibrationmarks 2202 may be compared to the model calibration marks 2002 in thecalibration CAD-model 2000 based at least in part on coordinates and/ordimensions of the model calibration marks 2002 and digitally representedcalibration marks 2202. For example, comparing the digitalrepresentation of the one or more digitally represented calibrationmarks 2202 to the model calibration marks 2002 in the calibration-CADmodel 2000 may include comparing one or more coordinates of the one ormore digitally represented calibration marks 2202 in the digitalrepresentation thereof with a corresponding one or more coordinates ofthe model calibration marks 2002 in the calibration-CAD model 2000, anddetermining one or more differences therebetween. The one or morecoordinates may include coordinates of respective ones of a plurality ofregistration points 202 respectively corresponding to locations ofrespective ones of a plurality of workpieces 116 onto which respectiveones of a plurality of extension segments 206 are to be additivelyprinted using the additive manufacturing machine 104. Additionally, orin the alternative, comparing the digital representation of the one ormore digitally represented calibration marks 2202 to the modelcalibration marks 2002 in the calibration-CAD model 2000 may includecomparing one or more dimensions of the one or more digitallyrepresented calibration marks 2202 in the digital representation thereofwith a corresponding one or more dimensions of the one or more modelcalibration marks 2002 in the calibration-CAD model 2000, anddetermining one or more differences therebetween.

Still referring to FIG. 25, the step 2504 of applying a calibrationadjustment to one or more CAD models may include transforming at least aportion of the one or more CAD models based at least in part on thecomparison at step 2502. The transforming may include rotating, bending,twisting, shifting, scaling, smoothing, aligning, offsetting, and/ormorphing at least a portion of the one or more CAD models.

In an exemplary embodiment, the one or more CAD models may include anextension segment-CAD model 800 that has a model of a plurality ofextension segments 802 respectively located at CAD model-coordinatescorresponding to respective ones of a plurality of registration points202 respectively corresponding to locations where respective ones of aplurality of workpieces 116 are to be situated when additively printingrespective ones of a plurality of extension segments 206 onto therespective ones of the plurality of workpieces 116. In some embodiments,applying a calibration adjustment to one or more CAD models at step 2504may include transforming at least a portion of the extension segment-CADmodel 800 based at least in part on the comparison so as to alignrespective ones of the plurality models of extension segments 802 of theextension segment-CAD model 800 with the respective ones of theplurality of registration points 202 of the additive manufacturingsystem 100.

In still another exemplary embodiment, applying a calibration adjustmentto one or more CAD models at step 2504 may include generating anextension segment-CAD model 800. The generated extension segment-CADmodel 800 may include a model of a plurality of extension segments 802configured to be additively printed onto respective ones of a pluralityof workpieces 116, and the plurality of models of extension segments 802may be respectively located at CAD model-coordinates determined based atleast in part on the calibration adjustment. The plurality of models ofextension segments 802 may be aligned with respective ones of aplurality of registration points 202 of the additive manufacturingsystem 100. The plurality of registration points 202 may correspond tolocations where respective ones of a plurality of workpieces 116 are tobe situated when additively printing respective ones of a plurality ofextension segments 206 onto the respective ones of the plurality ofworkpieces 116.

Now referring to FIG. 26, further features of an additive manufacturingsystem 100 will be described. As shown in FIG. 26, an exemplary additivemanufacturing system 100 may include a control system 106. An exemplarycontrol system 106 includes a controller 2600 communicatively coupledwith a vision system 102 and/or an additive manufacturing machine 104.The controller 2600 may also be communicatively coupled with a userinterface 108 and/or a management system 110.

The controller 2600 may include one or more computing devices 2602,which may be located locally or remotely relative to the additive visionsystem 102 and/or the additive manufacturing machine 104. The one ormore computing devices 2602 may include one or more processors 2604 andone or more memory devices 2606. The one or more processors 2604 mayinclude any suitable processing device, such as a microprocessor,microcontroller, integrated circuit, logic device, and/or other suitableprocessing device. The one or more memory devices 2606 may include oneor more computer-readable media, including but not limited tonon-transitory computer-readable media, RAM, ROM, hard drives, flashdrives, and/or other memory devices.

The one or more memory devices 2606 may store information accessible bythe one or more processors 2604, including machine-executableinstructions 2608 that can be executed by the one or more processors2604. The instructions 2608 may include any set of instructions whichwhen executed by the one or more processors 2604 cause the one or moreprocessors 2604 to perform operations. In some embodiments, theinstructions 2608 may be configured to cause the one or more processors2604 to perform operations for which the controller 2600 and/or the oneor more computing devices 2602 are configured. Such operations mayinclude controlling the vision system 102 and/or the additivemanufacturing machine 104, including, for example, causing the visionsystem 102 to capture a digital representation of a field of view 114that includes a workpiece-interface 120 of one or more workpieces 116,generating one or more print commands 1300 based at least in part on theone or more digital representations of the one or more fields of view114, and causing the additive manufacturing machine 104 to additivelyprint respective ones of the plurality of extension segments 206 oncorresponding respective ones of the plurality of workpieces 116. Forexample, such instructions 2608 may include one or more print commands1300, which, when executed by an additive manufacturing machine 104,cause an additive-manufacturing tool to be oriented with respect to ascan path that includes a plurality of scan path coordinates and toadditively print at certain portions of the scan path so as toadditively print a layer of the plurality of extension segments 206. Thelayer of the plurality of extension segments 206 may correspond to theslice of the extension segment-CAD model 800. Such operations mayadditionally or alternatively include calibrating an additivemanufacturing system 100.

Such operations may further additionally or alternatively includereceiving inputs from the vision system 102, the additive manufacturingmachine 104, the user interface 108, and/or the management system 110.Such operations may additionally or alternatively include controllingthe vision system 102 and/or the additive manufacturing machine 104based at least in part on the inputs. Such operations may be carried outaccording to control commands provided by a control model 2610. Asexamples, exemplary control models 2610 may include one or more controlmodels 2610 configured to determine a workpiece-interface 120 of each ofa plurality of workpieces 116 from one or more digital representationsof one or more fields of view 114; one or more control models 2610configured to determine and/or generate an extension segment-CAD model800 based at least in part on the one or more digital representations ofthe one or more fields of view 114; and/or one or more control models2610 configured to slice an extension segment-CAD model 800 into aplurality of slices and/or to determine or generate a scan path and anadditive printing area for each of the plurality of slices. Themachine-executable instructions 2608 can be software written in anysuitable programming language or can be implemented in hardware.Additionally, and/or alternatively, the instructions 2608 can beexecuted in logically and/or virtually separate threads on processors2604.

The memory devices 2606 may store data 2612 accessible by the one ormore processors 2604. The data 2612 can include current or real-timedata, past data, or a combination thereof. The data 2612 may be storedin a data library 2614. As examples, the data 2612 may include dataassociated with or generated by additive manufacturing system 100,including data 2612 associated with or generated by a controller 2600,the vision system 102, the additive manufacturing machine 104, the userinterface 108, the management system 110, and/or a computing device2602. The data 2612 may also include other data sets, parameters,outputs, information, associated with an additive manufacturing system100, such as those associated with the vision system 102, the additivemanufacturing machine 104, the user interface 108, and/or the managementsystem 110.

The one or more computing devices 2602 may also include a communicationinterface 2616, which may be used for communications with acommunications network 2618 via wired or wireless communication lines2620. The communication interface 2616 may include any suitablecomponents for interfacing with one or more network(s), including forexample, transmitters, receivers, ports, controllers, antennas, and/orother suitable components. The communication interface 2616 may allowthe computing device 2602 to communicate with the vision system 102, theadditive manufacturing machine 104. The communication network 2618 mayinclude, for example, a local area network (LAN), a wide area network(WAN), SATCOM network, VHF network, a HF network, a Wi-Fi network, aWiMAX network, a gatelink network, and/or any other suitablecommunications network for transmitting messages to and/or from thecontroller 2600 across the communication lines 2620. The communicationlines 2620 of communication network 2618 may include a data bus or acombination of wired and/or wireless communication links.

The communication interface 2616 may additionally or alternatively allowthe computing device 2602 to communicate with a user interface 108and/or a management system 110. The management system 110, which mayinclude a server 2622 and/or a data warehouse 2624. As an example, atleast a portion of the data 2612 may be stored in the data warehouse2624, and the server 2622 may be configured to transmit data 2612 fromthe data warehouse 2624 to the computing device 2602, and/or to receivedata 2612 from the computing device 2602 and to store the received data2612 in the data warehouse 2624 for further purposes. The server 2622and/or the data warehouse 2624 may be implemented as part of a controlsystem 106.

This written description uses exemplary embodiments to describe thepresently disclosed subject matter, including the best mode, and also toenable any person skilled in the art to practice such subject matter,including making and using any devices or systems and performing anyincorporated methods. The patentable scope of the presently disclosedsubject matter is defined by the claims, and may include other examplesthat occur to those skilled in the art. Such other examples are intendedto be within the scope of the claims if they include structural elementsthat do not differ from the literal language of the claims, or if theyinclude equivalent structural elements with insubstantial differencesfrom the literal languages of the claims.

What is claimed is:
 1. A method of additively printing an extensionsegment on a workpiece, the method comprising: pretreating aworkpiece-interface of a workpiece using an energy beam source from anadditive manufacturing machine, providing a pretreatedworkpiece-interface having received a pretreatment, the pretreatmentremediating an aberrant feature of the workpiece and/or theworkpiece-interface; and additively printing an extension segment on thepretreated workpiece-interface using an energy beam emitted from theenergy beam from the additive manufacturing machine; wherein theaberrant feature comprises one or more aberrant regions of the workpieceinterface that differ in elevation and/or that are at least partiallyaskew relative to a congruent region of the workpiece-interface, the oneor more aberrant regions having been determined from one or more digitalrepresentations of the workpiece-interface captured by a vision system,and wherein the pretreatment comprises additive-interface captured by avision system; and wherein the pretreatment comprises additive-levelingat least a portion of the workpiece-interface comprising a first one ofthe one or more aberrant regions and/or melt-leveling at least a portionof the workpiece-interface comprising a second one of the one or moreaberrant regions.
 2. The method of claim 1, comprising: determining theworkpiece-interface from the one or more digital representationscaptured by vision system; and transmitting to the additivemanufacturing machine, one or more pretreatment commands configured toexpose the workpiece-interface to the pretreatment.
 3. The method ofclaim 2, comprising: transmitting to the additive manufacturing machine,one or more print commands configured to additively print the extensionsegment on the pretreated workpiece-interface.
 4. The method of claim 3,comprising: generating the one or more pretreatment commands based atleast in part on the one or more digital representations of theworkpiece-interface; and/or generating the one or more print commandsbased at least in part on the one or more digital representations of theworkpiece-interface.
 5. The method of claim 2, comprising: determiningthe pretreated workpiece-interface from the one or more digitalrepresentations of the pretreated workpiece-interface having beencaptured by the vision system; and transmitting to the additivemanufacturing machine, one or more print commands configured toadditively print the extension segment on the pretreatedworkpiece-interface.
 6. The method of claim 1, wherein the pretreatmentcomprises: heat-conditioning at least a portion of theworkpiece-interface.
 7. The method of claim 1, wherein the pretreatmentcomprises: removing oxidation, contaminants, debris, and/or subtractivemodification artifacts from at least a portion of theworkpiece-interface.
 8. The method of claim 1, wherein the pretreatmentcomprises: modifying the grain structure of the workpiece at or near theworkpiece-interface.
 9. The method of claim 1, wherein the pretreatmentcomprises: additive-leveling a first portion of the workpiece-interfacecomprising a first aberrant region; and melt-leveling a second portionof the workpiece-interface comprising a second aberrant region.
 10. Themethod of claim 1, comprising: pretreating the workpiece-interface usingthe energy beam source to emit an energy beam at a first energy densityand additively printing the extension segment on the pretreatedworkpiece-interface using the energy beam at a second energy density,wherein the first energy density is from about 10% to about 100% of thesecond energy density.
 11. The method of claim 1, comprising:pretreating the workpiece-interface using the energy mean source to emitan energy beam at a first energy density and additively printing theextension segment on the pretreated workpiece-interface using the energybeam at a second energy density, wherein the first energy density isfrom about 100% to about 300% of the second energy density.
 12. Themethod of claim 1, comprising: additively printing the extension segmenton the pretreated workpiece-interface using an energy density of fromabout 70 J/mm ∧3 to about 200 J/mm ∧3.
 13. The method of claim 1,wherein the extension segment exhibits a relative density of from about0.950 to about 0.9999.
 14. The method of claim 1, comprising:pretreating the workpiece-interface based at least in part on apretreatment-CAD model, the pretreatment-CAD model generated and/ordetermined based at least in part on the one or more digitalrepresentations of the workpiece-interface; and/or additively printingthe extension segment on the pretreated workpiece-interface based atleast in part on an extension segment-CAD model, the extensionsegment-CAD model generated and/or determined based at least in part onthe one or more digital representations of the workpiece-interface. 15.The method of claim 1, wherein the workpiece comprises a compressorblade and/or a turbine bladed and wherein the extension segmentcomprises a blade tip.
 16. An additive manufacturing system, comprising:a controller operably coupled to a vision system and an additivemanufacturing machine, the controller comprising one or morenon-transitory computer readable medium and one or more processors, theone or more non-transitory computer readable medium comprisingcomputer-executable instructions, which, when executed by the one ormore processors, cause the additive manufacturing system to perform amethod comprising: pretreating a workpiece-interface using an energybeam emitted from an energy beam source of the additive manufacturingmachine, providing a pretreated workpiece-interface, wherein pretreatingthe workpiece-interface comprises remediating an aberrant feature of theworkpiece and/or the workpiece-interface at least in part byadditive-leveling the workpiece-interface and/or melt-leveling theworkpiece-interface; and additively printing an extension segment on thepretreated workpiece-interface using an energy beam emitted from theenergy beam source of the additive manufacturing machine; wherein theaberrant feature comprises one or more aberrant regions of theworkpiece-interface that differ in elevation and/or that are at leastpartially askew relative to a congruent region of theworkpiece-interface, the one or more aberrant regions having beendetermined from one or more digital representations of the workpiececaptured by the vision system; and wherein the pretreatment comprisesadditive-leveling at least a portion of the workpiece-interfacecomprising a first one of the one or more aberrant regions and/ormelt-leveling at least a portion of the workpiece-interface comprising asecond one of the one or more aberrant regions.
 17. The additivemanufacturing system of claim 16, Wherein the computer-executableinstructions, When executed by the one or more processes, cause theadditive manufacturing system to perform the method, the method furthercomprising: determining the workpiece-interface from the one or moredigital representations captured by the vision system; and transmittingthe additive manufacturing machine, one or more pretreatment commandsconfigured to expose the workpiece-interface to the pretreatment. 18.The additive manufacturing system of claim 17, wherein thecomputer-executable instructions, when executed by the one or moreprocessors, cause the additive manufacturing system to perform themethod, the method further comprising: determining the pretreatedworkpiece-interface from the one or more digital representations of thepretreated workpiece-interface having been captured by the visionsystem; and transmitting to the additive manufacturing machine, one ormore print commands configured to additively print the extension segmenton the pretreated workpiece-interface.
 19. The additive manufacturingsystem of claim 16, wherein the computer-executable instructions, whenexecuted by the one or more processors, cause the additive manufacturingsystem to perform the method, the method further comprising: pretreatingthe workpiece-interface using an energy beam emitted from the energysource at a first energy density, and additively printing the extensionsegment on the pretreated workpiece-interface using an energy beamemitted from the energy beam source at a second energy density, whereinthe first energy density is from about 10% to about 100% of the secondenergy density.
 20. A non-transitory computer readable medium comprisingcomputer-executable instructions, which, when executed by one or moreprocessors associated with an additive manufacturing machine, cause theadditive manufacturing machine to perform a method comprising:pretreating a workpiece-interface using an energy beam from the additivemanufacturing machine, providing a pretreated workpiece-interface,wherein pretreat the workpiece-interface comprises remediating anaberrant feature of the workpiece and/or the workpiece-interface atleast in part by additive-leveling the workpiece-interface and/ormelt-leveling the workpiece-interface; and additively printing anextension segment on the pretreated workpiece-interface using an energybeam emitted from the energy beam source of from the additivemanufacturing machine; wherein the aberrant feature comprises one ormore aberrant regions of the workpiece-interface that differ inelevation and/or that are at least partially askew relative to acongruent region of the workpiece-interface, the one or more aberrantregions having been determined from one or more digital representationsof the workpiece-interface captured by a vision system; and wherein thepretreatment comprises additive-leveling at least a portion of theworkpiece-interface comprising a first one of the one or more aberrantregions and/or melt-leveling at least a portion of theworkpiece-interface comprising a second one of the one or more aberrantregions.